From what I can remember (and I suppose that if I really needed to know I could look through the Charlie archives) Adam was not that difficult to potty train. Sure it didn't happen overnight, but once we learned the trick of giving him a handful of Reese's Pieces with every successful attempt the training was just about accomplished. Like everything else Alex seems determined to clear his own path.
It's like a circus act without the guy being shot out of the cannon. He says he has to go, gets you all geared up to take him, sits down on the potty, and then....then he...he..he makes a hissing noise with his mouth. Like I said tons of build up with no reward.