Baby wanting to stay awake at 3am😫

Coco

So my baby, went to bed at 630pm, slept .. had a quick feed around 9 pm .. and slept for six hours straight; which is the most He has ever slept, without waking... but when he started to squirm at 3am, he didn’t want to go back to sleep... so he did another quick feed, and then he stayed awake for almost two hours ... eventually at 445 am he fell asleep, as I held him, and he slept two hours, before waking for the day..... I’m wondering why ? Why the two hour stretch, that he’s wanting stay up and play... he wasn’t crying.. he just was not going back to sleep 😒🤔... being that he’s six months and leap is over, I don’t get it lol