TPBM means "The Person Below Me"
You justify the above statement by the person above you by saying True or False, and then supplying a new statement. Example:
User 1: tpbm loves chocolate.
User 2: True. tpbm eats fish.
User 3: False. tpbm likes the color pink.
User 4: False. And so on...

And here is the first post:

TPBM is very very happy this thread is back.