Don't know if you'll accept or if any will agree , but you asked.....
I view a 9 hole round as a sprint and a full round as a marathon. Some will handle trouble better than others , but I believe whether here at WGT or on the real course , somewhere along that 18 hole marathon WE WILL BE TESTED. It's golf. It's the karma of golf. It is a rhythm. A rhythm that is very similar to a "pre-shot routine". If that routine is broken in anyway. Step away , clear the head and start routine over. O.K. It sounds like you were in a rhythm. I can almost bet that between the 9'th and 10'th something occurred. You may have went to the bathroom , kitchen , phone rang , knock at the door , but something broke your rhythm , and you didn't "Step away" and you didn't "clear the head." Just like someone who's pre-shot routine was broken , but decided to go through with an uncomfortable shot...99.9% of the time they'll be rewarded with uncomfortable results. Hope that made sense to ya' Ren. To hold an 18 hole round together you can't bring a mistake made on # 10 to the 11'th tee with you. Because you'll make 2 more at 11. Then your bringing 10 and 11 to the 12'th....and the domino disaster has begun. It's GOLF. It's just golf. The answer is focus. Determined focus. Course management. Minimize mistakes. Refuse to be rattled.
Ace