Updating drivetrain on a mountain bike
Or to put it another way, you get most of your psychological benefit from mountain biking by riding, not by thinking about or buying upgrades.
We stop focusing on how to get more out of the riding we do, and the equipment that we have and, instead, shift our focus to the external (and entirely false) idea of “newer gear equals better rider”.
The reward comes in the form of increased levels of dopamine in this part of the brain, and dopamine feels really good.
In fact, every time you feel good about pretty much anything, it’s because of dopamine.
It’s about the process and the experience, not the outcome.
So, in theory, as long as your bike is actually capable of doing what you want to ride (and let’s face it, most of us ride bikes that are way more capable than we actually need), you can attain pretty much all of the things that mountain biking offers with what you already have.