Ever wonder about your husband?

My husband and I take turns at night every few days so we can each get some sleep. For example, I'll take the baby from 11pm to 5-6 am and then my husband will take him from then until around noon. We always take turns so it isn't the same person doing the same times. When I wake up in the morning and ask how the baby did, he always says he wouldn't go to sleep and he was up until 4-5 am fussing and crying! But tonight, it was my turn to do the "first shift" and it took me no more than a half hour to get our son fed and asleep in his crib. He slept for two hours, woke to feed, and went right back to sleep and has been asleep for an hour now. I'm wondering why my husband struggles so badly with him sometimes! And it makes me sad that he doesn't wake me and ask for help! I wish he would. If I hear my son crying for more than a few minutes, i go into the nursery and try to help but it's like he gets frustrated with me for trying to help and tells me to go back to bed! Is anyone else's husband like this?