I wouldn't call this a comedy

I saw this ages ago, one of the films they show on Australian TV time to time, late in the evening and was pleasantly surprised. However, I don't see why this would be considered a comedy. At the end of the day it's more a romance isn't it? I mean it's about a man who realises that the love of his live was his ex, and everything he couldn't be bothered to do for her, he is now willing to do for his next girlfriend/wife because of his ex, because he realised what he had lost out on and doesn't want to make the same mistake again.

Or did I just not get this film? I thought it was actually a bit sad.