Yes the PGA Tour is a higher standard than the European Tour, and yes Knox has won recently, but I don't think he's that special a player. He's a bit of a journeyman who is having a good bit of form, and not remotely intimidating.
Just as importantly, he has only been a member of the European Tour for a short period of time. He only joined when he thought he had a good shot of qualifying for the team, which is a bit opportunistic if you ask me.
You don't think most pros score at or below par most of the time? The only reason I say "most" is because pro also includes range pro's who don't really play or are not really that good but just declare themselves a pro.
There are several ways that I keep from blowing up and losing my temper. One is to look at the horizon or slightly above. For some reason, looking at the ground creates negative emotion where looking straight ahead or slightly up helps to curb anger. I forget where I read that, but it was many years ago and seems to work. The next is intentional breathing focusing on breathing out. If you keep your emotions in check. Negative emotions seem to encourage irrational thought (like @mcanadiens thinking he could get over that tree), where a sense of calmness brings on rational thought.