LO is 16 weeks and over the last several days, he has been going through SOMETHING--growth spurt, sleep regression, general fussiness. Before this hit, he was able to stay awake about 75-90 minutes before getting fussy/tired. Lately, he's only been able to make it about 50-60 minutes before having an overtired meltdown. Is it normal for wake times to decrease during growth spurts/regressions? I feel like he should be able to stay up longer at his age, but maybe not?