Not sure of exact years.

Mid 70s I got a Sony reel-to-reel tape recorder for Christmas that could do sound on sound and sound with sound. Spent many, many hours making multi track recordings, playing all the instruments. I learned a lot and had lots of fun in the process!

Early 2000s, getting Cool Edit Pro, my first DAW. I still have and use Adobe Audion 1.5 which is basically the same program, even though it is ancient it is still the best program I have found for recording and editing audio files, although I use Reaper for my main DAW now.

BIAB of course, also early 2000s.

Lots of other cool stuff over the years, instruments and software, but nothing I would consider to be game changers like the above.

Dave

Blue Attitude Website
Blue Attitude YouTube channel