We've all been there with those whimper kinds of moments.
I put a top together once and looked at it at least 100 times as I got all the pieces in the right positions. Put it together with back and batting, flipped it right side out, ironed out the wrinkles from the turning
THEN saw I'd sewn 1 little square the wrong way and couldn't leave it cuz threw the whole pattern off. And of course it had to be near the middle! Very carefully snipped the piece out and fixed.