(Talk about mental warfare, Diaz has gotten so far inside GSP’s head that the champ has apparently forgotten how to hold his hands during a staredown. Look at him, he looks like he’s trying to restrain his excitement while watching a cheerleading competition.)  The Nick Diaz crazy train continues to roll on, Potato Nation, and was on full display during today’s UFC 158: St. Pierre vs. Diaz pre-fight presser. First, when addressing why he had missed the open workouts — something Nick originally attributed to the UFC’s…I don’t know, flight scheduling? — Diaz claimed that he needed his sleep and that it was either I miss yesterday’s open workout or I miss this. Then, when questioned on whether or not he would pass his drug test this time around, Diaz dropped this gem: I think [at UFC 143] I tested for a metabolite or a nanogram, it was hardly [a trace] so I just did a little more than I did last time so, sorry if I don’t pass the test, but I think it should work out. I’ve passed plenty of them before, unless they just weren’t testing me. I wonder how much they test people around here (glancing at St. Pierre).  Seriously, this guy is like Sir Smoke-A-Lot, Burt Gummer, and the main character from Pi rolled into one tight, angel dust-laced doober. Are you still questioning whether or not Diaz is the antihero the MMA world so desperately needs? Check out the full video of the pre-fight presser after the jump for all of these highlights and more, and make sure to swing by our liveblog of UFC 158 on Saturday starting at 10 p.m. EST.