I learned the hard way. The less u cared the happier u get

Seems like it. When I worked at Walmart I was serious about learning how to deal with people, it was really hard for me because so many came into the store and every person was different. I was advised something similar, and it seemed like later the less I cared the better I got at the job. Maybe it was not worrying over the small things or things I had no control over.