We look for chemical rewards from our brains and bodies; all of us do. Some of us are less aware of this, some are more aware. The human system is built this way just like most other creatures. We differ, however, in which chemical rewards we seek, according to our own unique experiences, our own past, and our own physiology. For example I love the chemical reward I get from seeing a good science fiction movie or reading a great book ("great" from my own POV, of course.) I love the chemical reward I get from being on the water, being around animals, from music, from creativity, and from positive interaction with other people, especially friendly discussion, teaming and cooperating to do a project, sharing points of view, shared fun activities, and humor. I can trace that all back to my early childhood; it's a combination of the way I was born (my own physiological brain and system) AND the interactions of my childhood that were positive.

I, however, personally, do NOT get a positive chemical reward from completion of accomplishments, or showing them, or talking about them. That's not a goal I have automatically because of a chemical reward like many people do. I'm not seeking a good feeling from completing a project, or getting to my goal, or telling people about things I've done, because it doesn't really give me that. I like DOING the thing on my way to the goal, and being in the journey and the project, but the end of it, and announcing it, does not compel me.

Also probably from childhood experiences; I do remember getting good grades and getting more negative attention for them than positive. The same thing with performances as a child in both music and dance. Winning contests and awards also got me more negative attention than positive. Often it got me very negative attention; ridicule, shame, bullying, and ostracism. Even when there were a couple of members of my family saying "good job" about something, there were often much louder voices saying mean things, or making obvious overtures that I should be ashamed of myself for being the least bit proud of my accomplishments or confident in my abilities.

So I may actually have developed an aversion to reaching a goal due to the chemical anti- rewards my system has given me in association with accomplishment, and with others knowing about my accomplishments, or others seeing me doing something.

When we have negative associations with something, we create a virtual electric fence for ourselves. Our subconscious is protecting us from negative experiences or danger. It learned from past experiences: "When you get an A, you will get made fun of and threatened by other kids" which is much more imprinting on the subconscious than a pat on the head from a relative. It IS what happens, it IS reality, the subconscious knows this even if people are saying "no it's not true... you should be happy that you got an A."
When you are trying to learn how to skateboard, your brain learns that every time you take it out in the driveway or down to the school parking lot, you will get made fun and physically bullied. It has learned that when you take your skateboard out to practice, someone will push you down or take your skateboard, and at the very least they will sit there and make fun of you loudly, interfering with your concentration and ability to learn. Your BRAIN has learned this, even if when you get home the adults say "Oh just ignore them" or "You need to get thicker skin." (That family member would have done a heck of a lot more for you if they had simply come down to the school parking lot with you and spent time with you while you learned to skateboard. The brats probably wouldn't even have come around then.) So on top of your brain learning that every time you take out the skateboard you will be bullied, your brain also learns that no one is going to stand by you against bullies so you can actually learn.
After that "lesson" is learned, your subconscious says "Put that back" whenever you go to take the skateboard out. If you don't listen, you probably become anxious. This is the anti-reward, your brain saying "No! This is not good! Don't go there!"

We can also develop chemical reward associations from doing things that are both positive and destructive. The neurochemical response from "winning" can be addictive for many humans. When this addiction happens, a person may bypass his or her own values in order to get this reward, not unlike a hit of some other drug. The person learns that if they dominate another person in some way, they will receive a neurochemical reward.

The less-aware person often takes themselves very seriously in seeking this reward, because they often believe that the feeling they are getting is based in the EXTERNAL world. In other words: "If I win this game, I will be more important." or "If I win this argument, I will continue to be an important person." They don't realize the feeling of importance they are getting is from their OWN brain, not from the WORLD.
Of course when one or two people pat this person on the back for whatever they did, it reaffirms their belief that it's the world  that's giving them this reward feeling, not their own system.

This neurochemical reward system is one of the reasons why we often keep behaving in destructive ways even though we can see that something is not right.
Winning and domination over others is one of the most common neurochemical response addictions in the world, in the human species. It can be seen in other species as well, very clearly, however humans seem to be the only ones who destroy their own group with this addiction. Chimpanzees, our closest relative, do make war with one another and kill one another, and they attack others in their own tribe as well, but not like humans do. Bonobos, however, who are also called "Pygmy Chimpanzees", do not do this like Chimps or humans; they are adamant about peace-keeping, but they do this by substituting one reward for another: physical contact.

When a human is addicted to the neurochemical reward from winning and domination over others, he or she often seeks out ways to stimulate the chemical reward, to the exclusion of other things in life and the well-being of others, and of themselves.

They might try to make as much money as possible, or have the best work or sales record, they might be fixated on rising to the top of a company, organization, or field by any means.

They might find themselves in serious arguments with others frequently; starting a conflict or arguing with another person is a common way to try to "win", and therefore receive the neurochemical reward.
Denying the requests of others habitually is also a way to "win" and get the reward.
So is putting others down and judging them as "bad"; this is another way to feel like the "winner".
Joining a clique that excludes others based on physical differences is another way to get the "winning" reward. (No girls allowed, no Caucasians allowed, no fat or short people allowed, etc.)
Politicians USE people's addictions to this neuro reward to convince them to join their party (Their party is the "Good Person's Party..." better than the people from the other parties... )
Changing plans frequently and canceling them is another way; "I lead always, you follow always" will produce the Winning reward.
Haggling is another common way to receive this neurochemical reward.
Unfortunately cheating, conning, and tricking others also produces this neurochemical high.

Winning games and contests (ANY; sports, cards, music contests, spelling bees, chess, lotto, video games, etc)  is an obvious way to receive this neurochemical reward, and does not tread on ethics unless it becomes an addiction that leads to cheating, lying, stealing, exclusion of race or sex, sabotage, prejudice, and bullying.
(We see this every day, sadly.)

Criticizing others for pretty much anything produces this chemical reward, that's why there are so many people who criticize others with no regard for the impact it has on the person or the person's life, and often the criticism has no basis in reality or fact.

Throughout history "conquerors" have displayed massive addiction-behavior to the neurochemical rewards they receive from dominating other humans. Obviously destroying others does not improve the world, but that's what they would use as an excuse to do the thing that gave them their fix. It's still going on today, of course, all over the world, from large countries to small towns, to organizations, religions, anti-religions, and businesses.

Neurochemical rewards and un-rewards are a fact of life and science for we human beings, and most other creatures, so when we learn about them, especially our own, we can have more genuine autonomy and control over our own lives.