When he started training at 14. In a blog on his site a while back, he wrote, "The first time I ever bench pressed, I was 14 and I could do the bar for 8 reps. Max.
I was 114 pounds. I couldn't squat the empty hack squat machine, couldn't do a chin up."
He's also written about taking two years to get his bodyweight up to 135 before he got everything more in order.
And yep, the 350 method is a great "I dunno what to do, don't feel like much, so I'll do this"-fallback. Overwarm-ups are also huge eye-openers once you try them and see how well they actually help you perform. Pretty sure Poliquin, Waterbury, and Thibaudeau have all talked about using a similar principle.