Oddly enough I think my first 1/6th item was the GI Joe Doughboy accessory set (from the late 1990s?) followed shortly by a Tuskegee Airman. I was around 5 at the time.
A decade or so later the DML ST3 “Rick” followed. I was maybe 12.
Some years later, my first “proper” modern figure: the TCT ST3 mountain ops figure, “Dick Marcinko” (or whatever). Very dated construction but I love this one and the HS stands the test of time. I was 16 or so, and that was around the time I got involved with OSW. (5 odd years ago) Yes, kind of odd for a teenager to be heavily into 1/6th but I found it helped me develop patience, perseverance and attention to detail that served me well in school, on the rugby pitch and eventually in the army.
Now I have about 10 figure bodies, between which I cycle all my 1/6th kit in various combinations. I don’t really display any permanently, they’re all constant WIPs that I occasionally get around to photographing. I’d say at least 35% of all my 1/6th parts are falling apart due to overuse, but for me, kitbashing is a very active and constantly evolving hobby, more of an activity than a collection.