First timer - chick hatched rapidly...how exhausted is too exhausted??

This is my first hatch. I've been keeping chickens for a year, got four australorps then adopted a pair of neglected bantams and found one was a starved rooster and only masquerading as a hen. The lone bantam hen then needed some company to diffuse the bullying from my australorps. I decided upon a couple of daughters.

So, six of the seven eggs were fertile, and all six made it to lock down. It is now the morning of day 21. My first chick hatched about an hour ago. He pipped in a tiny way yesterday evening, then an hour ago he zipped and hatched in about 4-5 minutes. So fast. He flopped around a bit at first but since then has not moved. Is this level of exhaustion to be expected?? I'm assuming/hoping it's because he hatched so quickly....? Bit worried.