The First Program
I'm a bit fuzzy on exactly how old I was; my best guess is around 7, which would make this year the quarter-centenary of my marriage to code.
The household computer my siblings and I shared was a 48k ZX Spectrum. In those days even to load a game you had to learn your first keyword from the ZX's programming language: the LOAD command.
Even though I can't accurately remember my age, I still distinctly remember the first computer program proper I wrote. It was simple:
10 PRINT "Hello" 20 GOTO 10
Ah, those were the days, when you could casually write an infinite loop without blowing the whole world up!