Watched the death of our AIX systems (perhaps undead, as it really never goes away), the rise of PCs, the fading of Unix workstations. Desktop compute exceeding what could be done on my Cray time. The world circled back a few times: stand alone, client server, stand alone, distributed... with variations on a theme. Same is true about frameworks, languages, and development religions.
On reflection, creating new developers is a lot like parenting. You give recommendations, guidance, and opportunity. They still might footgun something, but you love them none the less. I'm proud of them and have launched some really solid Dev Leads over the years. So much satisfaction in shaping people.
The thrill of peeking/poking assembly as a youth is still there when I compile and the damn thing actually does what I set out to. Fixing broken is still very satisfying. Discovering that you can change a culture by leading was eye opening.
I still have no idea what I'm going to be, when I grow up. I consider myself fortunate.