Why do you think what you think is the right thing to do?

Answer 1

because your brain is accustomed to thinking things that are right according to it. a better more in-depth answer is that from your experiences you start learning. as you do your brain starts to "sway" to thinking some things are wrong and some are right (an example is how someone thinks stealing is good because some people should give more, although I never encountered something like this). your brain deletes thoughts that it thinks is wrong (you think these thoughts, but soon push them away) and you choose a thought that you think is right. you might want to think your brain chooses its experience answers, but sometimes you persuade it to think differently (or it changes its answer itself).