oh goodness, so many reasons!!
I never intended to be a co-sleeping family - but when ds was born, he would only sleep laying on my chest. Frankly, it freaked me out because I had only heard how dangerous co-sleeping was. Thank goodness I had fallen in love w/Dr. Sears during pregnancy so was somewhat familiar with the Baby Book... As I read and thought more, it just made sense... My son and I "knew" each other in a way that either of us knew anyone else. He had slept with me every night while being made, so of course he still wanted that. And he was completely helpless - so of course he still needed that. Again, it just started to make sense from a biological/anthropoligical way...
Then we were bf'ing, and as others have said, its much easier to just roll over than to get up. I'm a light sleeper to begin with - and getting out of bed totally disrupts my night clock, so I'm up for hours then. This way, we were all better able to sleep...
Also, I am a hypervigilant person - I wake up at the slightest noise, I worry for no reason about robbers breaking in and fires and stuff. I figure out ways in which we could escape quickly. Imagining my newborn (or now toddler) in another room, not close by, terrified me...
And, whenever he has gotten sick, I think about what might have happened had I not been right there. Twice he has thrown up silently in the middle of the night - once turned into a very violent stomach virus, where he was really to weak and scared to even cry. If we were in seperate rooms, I never would have known
And another time, his breathing got severly affected by a cold - so much that it had affected his heartrate, etc. Again - I'm glad I was right there...
Plus, I simply enjoy it. I work part-time, so I feel like I never get to spend enough time w/DS - this gives me 11 or so more hours a day with him, getting to know him and be attached with him on a very intimate level. I love cuddling him down to sleep, and playing with him as soon as he wakes up in the morning. I love it when he is 1/2 asleep in the middle of the night and sweetly says "MaMa" in the happiest voice as he reaches out and touches me. It makes me sad to think about the babies who reach out for comfort, for their mama's, only to find substitutes.... I love it when, like last night, he gets tickled by something in his dreams and starts giggling... Its too adorable for words - and I would hate to miss it...
Although I have definitely had my personal "crisis of faith" when it comes to co-sleeping (are we doing the right thing?, please I need more sleep, will he ever sleep through the night?, what are we going to do when the new baby comes?!), overall, I feel that we are doing the right thing for our son, that he loves it - and so do I!