Keeping a job, which led to getting an apartment and having bills. When I started that job at 21, I still identified with the teenagers. I didn't take my job serious, but somewhere in the almost 7 years at that job I grew up. I became one of the most knowledgeable and reliable employees. Things that are popular in music and fashion just seem so contrived and silly. The perspective of seeing just how temporary something is "in". I have no desire to wear the latest thing, or have the latest haircut because to me it looks dumb and trendy, and that in 5-10 years the whole thing will be dated.