I have very, very foggy recollection of being at Douglas Park with my dad one night - it must have been Hamilton vs Alloa, as I recall an auld guy screaming "NEVER MIND HAMILTON ACCIES, C'MON ALLOA!" right beside me. This would have been early-mid 80's.
The first football occasion I really remember being at was the 1987 Skol Cup Final that Rangers won on penalties vs Aberdeen. My brother "lifted me over", and I didn't see a single thing.
First Livi game for me was the opening of the stadium in November 1995. Even as someone in their late teens at the time, watching the stands near completion was achingly cool.