When you lose interest in a program, your last duty to it is to hand it off to a competent successor.
Any tool should be useful in the expected way, but a truly great tool lends itself to uses you never expected.
Good programmers know what to write. Great ones know what to rewrite (and reuse)
Why the hell hasn't wxPython become the standard GUI for Python yet?
Release early. Release often. And listen to your customers.
When I hear the words "social responsibility," I want to reach for my gun.