For virtually everything in life (not just cars and taxes), there's always "maybe I could have done better". This attitude is a recipe to be always dissatisfied

For virtually everything in life (not just cars and taxes), there's always "maybe I could have done better". This attitude is a recipe to be always dissatisfied and unhappy. The approach should be "did I do a good job?". For example, if you were able to get $1000 off on the car but most people are able to get only $800 then the answer is "yes" and you should be happy and content even though someone may have gotten $1200 off. Once you start evaluating your actions and decisions like that, life becomes much happier and content.