When is it safe to let a baby sleep alone?

Okay, so when's it safe to let a baby sleep alone? Man, that's such a loaded question. It's so personal, you know? I remember with my little one, Liam... just the thought of him being alone in his own room, it practically made my stomach churn. Seriously. I’m getting a little anxious just thinking about it now! We kept his bassinet right next to our bed – practically touching it – for, like, six months? Maybe longer, I can't even remember clearly; those early days are such a blur. It just felt… safer. I needed to hear him breathing. To be able to peek over and see his little chest rise and fall. Didn’t want him too far, you know what I mean? Plus, all the advice about SIDS and having them close by… I mean, who was I to argue with that? I felt like I was clinging to that advice for dear life. Like, if he was even a foot further away, something terrible might happen. It’s irrational, maybe, looking back. But in the moment? Totally understandable. Right? Any other moms feel that way?