I have always practiced co-sleeping. All three of them have slept beside me from birth until they are about big enough not to cry when they see that I am not beside them when they get up in the morning. In my case now, my youngest is the one who still sleeps beside me. refer to older post: his umbilical cord is still attached to me.
I gotta say that I can't help but compare their movements during the night.
The eldest would move a lot and would ask for 2 or 3 bottles thru the night until he was about 3. The second one would hardly move! He was a very well behaved bedmate who stopped asking for a bottle during the night when he was about 2. The littlest one, who happens to be my current snuggling buddy is, I have to say, the most active one! Thankfully, he also has stopped drinking milk thru the night before he turned 2. But thru the night, I often wake up to a kick in my back or a hand on my face or his head on my tummy.
As I speak, his left foot is on top of the keypad of my laptop.