That's the problem with momentum. Lose it and you can't always get it back, as Manchester United discovered at Old Trafford on Wednesday night.
United didn't just miss out on a place in the FA Cup final on Sunday when they changed a winning formula and went down to Chelsea.
They lost the rhythm that has built up since the restart, the chance to extend a 19-match unbeaten run and the confidence that could have carried them more convincingly towards a Champions League shootout at Leicester on Sunday.
Instead, they laboured to a draw against West Ham on a night when Ole Gunnar Solskjaer kept faith with goalkeeper David de Gea and discovered another United player who is good with his hands.