...stop learning from the various smart (and not particularly intelligent) things that I do. I know plenty of people who I've met in passing and who are close to me who say, "I'm too old to change," or, "I like who I am, I'm not going to change."
Folks, you're wrong for that.
I'm not perfect, far from it; neither are you. Since we are not perfect we should always be aiming to better ourselves. There are so many aspects of life which would be so much more beautiful if people were really willing to learn from their mistakes and other people. Politics is one of the sad examples. In politics it does not pay to admit that you have learned from your mistakes; the status quo is to deny even having made a mistake. That, of course, would show weakness and inferiority and god forbid we allow ourselves to just be the flawed works in progress that we are, it might be embarrassing.
I'm not just talking about learning that boiling water = burns; that's the simple stuff. I'm talking things like expecting someone to act in one manner in a situation because you would = unreasonable. I'm talking about learning things that fundamentally change me and make me become a better person. I'm talking changes that scare me and changes that challenge me. Sure, I could be complacent, I do plenty of things in a positive enough manner that I could survive living this life, refusing to change, being the same me that I'm at right now and say it's good enough; it isn't good enough though.
The second I stop trying to become a better person, and the second I stop learning from my mistakes, is the second I am done with this life. Only then will I truly be done.