<human>: Could you distill the essence of the text into 1-3 sentences?

When I was four or five, maybe younger, I remember making friends with this kid called Gregory. Some of my oldest memories (that I can place) actually involve me going to his Birthday party at a now defunct restaurant, and he mine. Not long after, I moved (with my parents of course) into a new house and school – 20 odd miles away, leaving Gregory a welcome, but faded, footnote in my childhood index.

Fourteen plus years passed, and I enrolled late into College. (Having dropped out almost immediately a year before due to health reasons.) The guy I was sat next too on my first day? That very same Gregory – except now he went by a much more inventive handle: Greg. We quickly became friends (again), ignorant of our shared past like something out of a Dicken's novel.

It wasn't until my mother met him in passing, months later, when questions were asked and two and two were finally put together. ("Did your Mum work [here]? Do you have a sister called…? Did you have a party at…? Four!") 

Recollecting memories of a shared past with an almost stranger was understandably weird! He was the oldest friend I'd not long met.
<bot>: Moved away from my best friend was I was little. Grew up (+14 years). Went to college. Dropped out. Went back to college. Sat next to same childhood friend. Became friends again by accident.