Any older middle aged men get thrown off when someone wants to fist-bump you when you’d rather shake hands?

There was this young guy at work, looked to be in his 30s, I dealt with a certain issue. He was so grateful that he held out his fist to bump me, but then he saw that I extended my hand, so he shook my hand instead. Not sure if it’s a generational thing, but I like giving handshakes