Econometrics Agony

Agony is when ManU/Liverpool/Chelsea/Arsenal lose to one and another --depends on what team you root for.

But for ones who ever do econometrics exercise for their paper, few beat the definition of agony in a short haiku by Keisuke Hirano that appeared in the highly recommended Angrist and Pischke's Mostly Harmless Econometrics.

T-stat looks too good
Try clustered standard errors --
Significance gone

OK, it's not as depressing as infamous Hemingway's six-word story ("For sale: baby shoes, never worn."); but trust me, if you ever work with regression and robustness test, you would share the pain.