1. The serious medical condition of forgetting to go work out. Or not working out due to laziness and consequently packing on some pounds.
Chantelle: "Man, what happened to Mike? He used to be so fit and now he looks like a whale!"
Dan: "Yeah, he really caught a bad case of abnesia."
Dan: "Yeah, he really caught a bad case of abnesia."
by Danderson777 June 13, 2013
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