The thing about memories is often people (unconsciously) make them up afterwards, or they combine memories of events that are actually separate into one incident, or they fabricate them based on photos they've seen and stuff like that. My sister claims to remember sitting in a car seat in the back of my dad's old green citroen... the thing is he sold that car when she was about one year old, so there's no way she could remember - but there is a photo of her in a car seat in the back of it.
But no matter how long ago it was, it's not surprising if people can remember at least some details from their first game, assuming they were old enough to have done so. In my case I had to nag my dad for ages to take me (he wasn't a football goer or even a football fan, being an immigrant from a non-footy playing country), it was a night game which heightened the excitement, and City obviously turned out to be a very important part of my life. So the few specific memories I have are very clear and vivid in my mind.
But no matter how long ago it was, it's not surprising if people can remember at least some details from their first game, assuming they were old enough to have done so. In my case I had to nag my dad for ages to take me (he wasn't a football goer or even a football fan, being an immigrant from a non-footy playing country), it was a night game which heightened the excitement, and City obviously turned out to be a very important part of my life. So the few specific memories I have are very clear and vivid in my mind.