Jellies over 40, what "absolutes" have you changed your mind about since your 20s?

A few decades ago I felt very strongly about a number of things that I now look back on and chuckle or, in some cases, wince about. My friends and I were talking about this the other night, we all had a few things on that list, just wondering what yours are? One of mine, for example, was that I would never let my child eat fast food. Ever. Imagine my surprise when I realized how convenient it is!