The fact that he actually mentioned means it's important to him too. He cares and thinks about it and although he isn't ready it's better to wait, even if you know you are meant for each other.

s**t happens.

People up and leave everything they know and marry someone and things still don't work out, despite the commitment involved.

Marriage isn't just big for women, it's also big for men.

He could simply have a lot on his mind.

Kinda like the way I can't study for an exam if I have work beforehand. I go crazy with frustration from just trying to schedule things out. o.o'''

Or something along those lines.

This is definitely a waiting situation. Unless you end up waiting like 20 years or something. Then I'd draw a line. o.o'''