From a scoring perspective: My approach into No. 18 on Lake Placid Club's Links Course. I was playing very well that day and was 2-under-par going into No. 18. Talked myself into clubbing up for my approach due to the slight elevation from fairway to green, but forgot to take into account my adrenaline. I flew the green by about 10 yards, short-siding myself. I hit a decent pitch and lipped my par putt. I still shot 1-under, but a score of 69 would have been oh so sweet.
From a more architectural perspective: A birdie putt from the front of the Elkridge Biarritz to a back hole location. I had the local knowledge and just ignored it...terrible self-inflicted read turned a really fun 90-foot putt into a terrible three putt.