My first encounter;
Computer lab at highschool late 80's, populated by C64s. My friend brought in his 1Mb A500 and the teacher did a 2hr demo session, showing games, apps, demos etc.
We were all blown away...
I knew I'd never get the money to get my own and besides I had only just bought my C64c. But it left a lasting impression and I eventually got my own s/h A500 a few years later. Followed by an A1200 ...and several more A500s.