I was a moto guy who also rode a bit of BMX, played some ball sports, and ran for fitness, but I remember watching ABC Wide World of Sports when they would do their TdF weekly recap show, maybe starting in '86 (LeMond). I was always impressed with being able to pound out the miles day after day, but it didn't hook me too much. I also saw a really wet edition of P-R. Flash forward to 1991 when I got out of the Army and was looking for an athletic outlet. I bought a mountain bike on a Tuesday, and did a race that Saturday. It was joylessly miserable, and I have been riding ever since. I didn't really get 'drawn in to pro cycling' until '93 when I decided that I might be able to 'make a living' racing mountain bikes so I started training with a group of roadies who where always talking about Euro road racing. I started reading about it quite a bit, and watching whenever it was on USA TV or when someone got a VHS tape of races. The Internet also started making it easier for USAers to watch Euro races. Also at that time, it was pretty common for pro dirt guys to join composite teams at road races so I was literally drawn in to USA pro racing.
So to the OP, my involvement drew me to pro cycling I guess.