I like Nike's tagline, "Just Do It" and I think that we shouldn't over analyze and hem-and-haw or delay doing something. It's a weakness I must overcome. Just do it.
But I realize that "Just Don't Do It" is an equally good motto. I know a couple of friends who will just give me "the look" if I even mildly suggest something that is off track. "The look" tells me "don't do it!"
If some activity has no benefit but plenty of pitfalls, their "just don't do it" message gets me on track. There are some things that we should just not do. Not because of being holier than thou or to be better than the fellow man or even as a programmed parent-child ego state response, but just because there is absolutely no benefit and plenty of drawbacks. That look that my friend gives is one of "don't be a stupid fool", and to tell the truth, I'm thankful for my friends for it.