That's weird. I had to take testosterone gel packs when I was in my early 30's.
The conditions that an individual have are not indicative of the conditions the average person that age has. You had low testosterone in your early 30's... but that doesn't mean that 95% of men had clinically significant reductions by age 36 (nor that by that age, did 95% see the numbers begin to decline).
And it depends on how they're counting "95% of men over 35 years." At best it's misleading to tell a 35-40 year-old they might need testosterone supplementation while using data that includes frail 95-year olds who's pituitary gland has stopped working altogether.
[OT]They've shown that professional boxers, kickboxers, and some football players have extremely low levels of it, most likely due to head injuries affecting the pituitary. Crazy stuff.