...that I recall with fondness:
1) My first computer, a Sinclair ZX Spectrum +2 computer with - wait for it - a whole 128k of memory. I still have it stored away somewhere; great stuff. I loved that computer. The games were in a league of their own: Dizzy, Colin the Cleaner (don't laugh - it was fab), Cobra, Outrun, Blizzard Pass and my favourite, Elite. It used to take about an hour to load up (using the built-in tape cassette recorder) and then promptly crash and refuse to run. Excruciatingly frustrating at the time, but I look back on it now and it makes me chuckle.

2) My Raleigh Burner bike with its "mags" wheels (no spokes here, no sirree). It was the mutt's nuts and the envy of all my friends; I remember my parents paid about £100 for it at the time. My friends had lowly BMXs and were forced to ride in my shadow. I could do bunny hops nearly a foot off the ground and all kinds of other freestyle movements, except the elusive wheelie, which I just couldn't master for some reason. Tried it on a quiet road once, pulled too high and flipped the bike up and completely over, with me ending up on my back. Luckily, the only witnesses were the birds in the trees (I hope - I didn't hang around long enough to check).
3) Transformers (robots in disguise). ThunderCats. Dangermouse. MASK. He-Man and the Masters of the Universe. And possibly my favourite cartoon of all time - Dungeons and Dragons. Did they ever get back home in the end? They don't make them like they used to, I'll tell you that for nothing.
4) School summer holidays - those six weeks used to last forever and spending most of it with a select few of my friends from primary school was just the best feeling in the world. Playing on my Spectrum computer. Going out on our bikes. Watching classic cartoons on TV. I possibly didn't think so at the time, but those were the best days of my life.
5) My first girlfriend. Her name was Marissa and she was the cutest thing since the last cutest thing that caught my roving, yet innocent, eye. We were about nine-years-old and used to pass secret love notes to each other in class. Then I got myself another girlfriend who was in the same class. I still feel guilty about two-timing her.

Ah, the memories.... I'm sure there are more, but that's all I can think of right now.
(This thread was inspired by Adrian's Egyptian thread, which I didn't want to take wildly off topic).
