Seems we are convention contemporaries.
My first con was Confusion in 1978
Went for Sat afternoon only, after taking my SATs (so it was probably June.)
There have been a couple years where I didn't have the $$ to attend or was overseas so I could not attend a con, but all in all that is 26 years of Convention attending.
Within a couple of years I discovered Filk, Anime (called a less pc name then), Costuming, Met Gordy Dickson (and drank his scotch), and, and, and....