M.D.
I'm a mom of 3 and my youngest will be 3 soon and I chalk it up to a phase that they go through. Much of my experience was that they are overstimulated or this was the prime time that my kids started dreaming. My son would wake up and want to play because of something he dreamed about or had him spooked so he just needed something to take his mind off of it. My daughter would wake up talking and then wouldn't remember and then need a drink or go potty or want to come sleep with me. Be happy you were blessed to have an awesome sleeper to begin with but know this should only be a phase.