I'm at the end of my life. At 25 I decided to get really good at one or two things so I could at least make a living when needed. It was hard to drop other goals but I knew that I could get hired if I was better than 80% of fellow job candidates.

Now that I'm officially retired I'm STILL trying to achieve expertise in multiple areas, but it feels good to know that I was able to support my family and build a retirement fund b/c of my modest expertise.