Hello Paul!
I'm the same way. I was perfectly happy and content having completed my T206 Hall of Famer run (well, minus the obvious two cards)
Then I came here and started seeing all the commons!
Not too long after that, I was hooked!
Now, I'm just over 50% on the set and every night when I'm looking on ebay, I'm asking myself:
Self, what the HE!! are you doing!!!!!
Luckily, I'm not married (my "significant other" is my card collection)
Anyway, welcome to the club.....we all serve to enable each other!!!
Steve