Most of the people I know started coding before 14 years of age. I think it's difficult for older people to learn simply because older people don't have the time to commit to coding, since there are other obligations, like work, etc.
That's selection bias. I'm guessing you don't know wide amounts of people who learned to code something real after finding VBA was a few miles short of where they needed to go.
Work in a non-computer industry, you'll see several people who learn to code at 25+ or even 35+. They often don't take huge amounts of self esteem out of this (it's just another thing they do at work) and don't go hog wild for "geek culture", but they program nonetheless. They often think people who do go far into that stuff will be contemptuous of them, so may be hiding it from you. I know I have a reputation of being nice to everyone but liars, and have had lots of questions on this stuff from random professionals about their personal coding
There is little that is special about this thing we do in the grand scope of things that humans do.
BTW, professional assistant/secretarial types love them some VBA/bash scripting once they figure out what it is (a way to do less repetitive work). I've seen 3 take up automation of excel or word.
Wish they made a website like that for C++.