Baby necessities

So as a FTM I have gotten lots of comments on how little I have on my registry, might I add that I did my registry myself and with me not having any children yet, I wasn't entirely sure of how much or what to put on there. I just had my baby shower yesterday but I have another one next Tuesday at my job. So my question is, what are some things you didn't get enough of or didn't even think about when registering that you found were major necessities? Thank you!