The teeny tiny clothes and diapers!!! I loved those. Even now when I'm shopping for her 18 month outfits, I pick up the newborn or 3-month stuff and kind of hold it close. I'm sure I look ridiculous but I miss that.
I just thought of this today - I miss the infant car seat. It was so easy to put a blanket over her and head out the door. Now I have to put her hat on, coat, mittens, boots, and carry her into and out of the car.. and it's damn cold here! I also miss snuggling on the couch with her when it was way past her bedtime. Now I try to follow a bedtime routine but it was really nice when it didn't matter when I put her down for the night.