The best, arguably most fun part of being a parent is learning about this new person you've created. As you spend time with them throughout the day, you get to see how they handle a wide range of ordinary, every-day scenarios; revealing their personalities little by little and as they evolve. If you co-sleep or bed-share with your baby, you get an extra few hours of careful observation (even if you're half-asleep for some or most of it), which I personally find to be pretty cool. In other words, there are lots of things you learn about your baby when you co-sleep.
I'm one of those moms who read up on the various sleeping options before giving birth, but planned to co-sleep with a sidecar attachment for a little while before moving our baby to a crib in his own room. (Isn't it hilarious how many assumptions you make about your life as a parent, before your kid arrives? Like the child doesn't get to cast a vote?) Of course, when he got here, I quickly learned that he had other ideas and a very steadfast plan of his own. I also learned that I value sleep over winning a battle of wills with an infant, so that was that and my carefully crafted plan went out the proverbial window.
Luckily, we were able to make co-sleeping work for us, so we could all get at least some sleep. As my son continues to grow, we're attempting to shift him more towards his own space at night, because co-sleeping with a toddler is a much different experience than co-sleeping with a baby. While I do look forward to the day when he consistently sleeps in his own bed, I've also really appreciated lots of the little things about my son that I've learned and witnessed, because we sleep in the same space. Some of those things are sweet. Some of those things are funny. Some of those things are, well, not as endearing. Still, there's some stuff you just wouldn't know (or know as well) if you didn't see it with your own sleepy eyes, like: