system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What exactly makes certain things feel satisfying? (Like popping zits, things geometrically arranged, etc) Is there a term for this?
gpt
I think your question is "Why are some random things still satisfying to us?"

The answer is evolution. Lets deal with the 2 different topics you have here: OCD and Bodily Cleansing. The zit popping first.

This one is odd. Popping zits is almost fun. Often painful, its still satisfying when it finally pops. And over the next few days, picking off the little hard drop of plasma is also satisfying. So is picking a scab, cleaning your ears, picking/blowing your nose etc. They are satisfying because they are related to things that in the past would have aided our survival. 

When you pick a scab, for example, even if you bleed, it feels satisfying. They usually itch a little, and they catch on things, and eventually you are just there going pick pick pick. Well scabs, although helpful for keeping germs out of open wounds, are also dead skin and plasma, and are easily infected. Picking them encourages fresh bleeding to cleanse the area of the wound, encourages fresh skin growth and removes necrotic tissue. Useless but satisfying for a skinned knee. Super important for a wound sustained from a wild animal. Similarly zits are a build up of puss. Its probably a survival trait to remove infection, no matter how minor, so we are hard wired to enjoy it. 

As for OCD, again, its survival. But it seems to be an expression of excess survival instincts. The brain likes to find patterns. In the wild, these patterns were "That man from our tribe. That man not from our tribe. That mark on tree mean bear." etc etc etc. Now we have fewer stimuli so some people thing OCD is an expression of these traits. It could also be as simple as geometric patterns are easy to create and its easy to spot when something is displaced. It may have been an early anti theft device, placing your personal items in a grid. Or laying sticks in a formation that was visually pleasing outside of an animal den to see if it is still being used, the sticks having been displaced during the night. 

All of this is conjecture. But the chances are the reason these things all feel satisfying is because they are left over survival instincts, and the release of endorphins (those chemicals in the brain that make us feel better) is because our brain once needed us to keep doing them to survive. 

Hope this helps!