My parents and I spent three weeks in Ireland every year from the time I was 2 to the time I was 10. I was thus a bit too young to remember my very first flight, which would have been JFK-SNN on an Aer Lingus 747-100 in the fall of 1983.
My most memorable Aer Lingus flight was the one we took in the summer of 1991, when I was 9. I was able to see the aurora borealis out the window for much of the flight while listening to "Ice Ice Baby" and other pop songs my parents didn't otherwise let me listen to in front of them.

A 6-hour flight seemed so l-o-n-g to the little kid I was back then, while nowadays at age 24, of course, it feels like nothing.
Another prominent memory is the stench of the smoking section (which I believe Aer Lingus still had even on my last flight on them in 1992)...my dad was a pack-a-day smoker in New York and a two-pack-a-day smoker in Ireland.