Because dads don't always think like moms.
Rather than opting for the baby memory book thing, which mostly will just sit on a bookshelf waiting for someone to fill in all the stuff years later, you may want to take a calendar and just enter stuff, as it happens, into the boxes: “first smile,” “first wink,” “first solid food…” You get the idea.
If you don’t have a calendar sitting around and need some help, check out baby calendars, where you’ll find a selection of calendars with stickers to act as prompts for you.
Calendars also make a great place to stick all the souvenir papers that come with parenting. We kept these calendars going through age 2 when the rate of change slows significantly.