I've heard this from a few people, and I don't understand it. The whole idea of paternity leave is to allow you to care for a newborn -- it's not supposed to be a vacation!
I think a lot of fathers-to-be imagine their newborns spending most of the time sleeping, leaving lots of time for work/learning/whatever. In reality, it's rather unlikely you'll be getting more than a few hours sleep yourself!
I've heard this from a few people, and I don't understand it. The whole idea of paternity leave is to allow you to care for a newborn -- it's not supposed to be a vacation!