I think that statement is true only for time-constrained arguments. It takes time to research and understand the prerequisites to any "advanced wisdom," so to speak. Likewise, it takes time to understand the flaws in untrue things, and to notice your own biases. Finally, even if you understand the evidence and arguments leading up to some great insight, it takes time to fully understand the ramifications of the idea. If you're time-constrained like in your example, your past self simply can't process everything fast enough and the absurdity heuristic wins.

The one positive thing this law has lead me to is a much higher tolerance for bullshit. I'm no longer so quick to dismiss ideas which, to me, seem obvious bullshit.

This is where I have to disagree with you. There are plenty of ways to quickly and accurately rule out most incorrect beliefs without accidentally ruling out correct beliefs. Many of them are mentioned on this site.