I have come across a lot of folks in my life who have comfortable lives, by virtue of working hard for it or being born into it, and too have observed that they fall into a slump, such that a major shift to that lifestyle can bring them down to their knees. I am, frankly, scared of landing in a similar situation. I do try to keep myself sharp by reading/trying out things here and there, but since I don't apply them to a meaningful extent, I have hard time trusting these.
As far as sharing the stuff I know is concerned, I have held an opinion that I don't have any new knowledge. Most of what I know has been derived from works of others, and all of that is already available out there. So I have felt that duplicating that information just increases entropy without any meaningful gain to anyone. That is why I haven't made an effort in that direction.
I might sound like a bad human saying this, but I think I have been largely apathetic about the world. I do think about the worldly issues, usually going into a zone such that I am unable to sleep at night, but I don't think I have ever taken a step to contribute to it meaningfully. I will take up your suggestion and see if I can start putting my skills to use in that direction.