I made this for my boyfriend for Valentine's Day. It took much longer than expected..I was working on it for 5 days, so at least 10 hours total time, possibly more. However, it was a really easy project and I had a lot of fun making it, and my boyfriend loved it. When he started to read it, he said, "Wow, I think I might cry!" Luckily, there was enough funny ones mixed in there to keep him from choking up ;)
It's a really sweet idea and I definitely recommend this project. Don't be intimidated by needing to list 52 reasons either...write them up on paper first, and once you get going, it's pretty easy to think of them :) Don't stop at just 52 on your list either...it's nice to have choices. I made a list of about 65, and I ended up having to think of another 7 or 8 towards the end of the project because I didn't feel some of the first ones I came up with were good enough.