Pertains to really botching up a situation and/or the process of choking in a sports situation.
Tends to portray totallyfucking up someone's blissful morning moments and can be followed with equally impressive screw-up scenarios -- however the act of finding a turd in one's oatmeal is the trigger-phrase.
What the hell was he thinking with that presentation?? Jesus-f'ing-christ, he really shit in the oatmeal this time -- and wiped his ass with the omellete!!
All they had to do was make 3 free-throws at the end of the game -- they really shit in the oatmeal that game.
It's when you take a shit and find whole bits of corn staring back at you. An especially chuncky turd filled with corn -- in theory, slow-cooked XXX chili could be replaced where XXX = peanuts, twizzlers, peas, etc.