It's not really a fear so much as a growing certainty that I will never achieve anything worth speaking of (not even the small victories of the average non-descript man), improve anyone's life in a meaningful way, socially be anything more than an intentionally insufferable annoyance, and in general acheive nothing more than basic material survial. And that, only barely.
That I should pass from this earth having spent most every waking moment of my whole life trying to learn anything I could, to the best of my limited abilities without having used a lifetime of training to improve the lot of my species in even the smallest way shape or form.
There's old Calvin and Hobbe comic I can't seem to find online, where Hobbes asks Calvin what he would wish for, if he could wish for anything. Calvin of course has a long and elaborate list of extravagent items he would wish for. Hobbes' reply is that he would wish for a sandwich. Calvin declares that that to be the stupidest thing he's ever heard. The final panel shows Hobbes, enjoying a sandwich. He taunts, 'I got my wish', while Calvin's face bears an expression that indicates he still hasn't learned a thing.
Well, I've always the kid who wished for the sandwich but wound up with an empty plate. Maybe I should have demanded the trillion billion dollars, space shuttle, and private continent after all.