1) 24-year old guys who are happy living at home playing Playstation all day don't just wake up one morning with a dose of ambition. It's not like the BF is going to all of a sudden start acting like an adult. He is an adult. What you see is what you get. You love the guy - but do you want to spend the rest of your life with this guy - specifically *this* guy - the one he is now - not the one you hope he turns into?
2) When the best-looking guy in town slips you his phone number, he's after a booty call, not a lasting relationship. Not that there is necessarily anything wrong with that, just understand what you are getting into.