Moving In

My boyfriend and I have been dating for over a year. I’m going to college and he is working and getting certified for heavy equipment operation. We have discussed getting an apartment together after he gets a career in the field, which would put us at nearly a year and 8 months of being together when we would actually move in. This is something that we both are comfortable with, have talked about for a while, and are ready for. My only problem is that I’m 19 and he is 22. When I mentioned it to a friend her first response was “you’re only 19!” Is she right? Should I wait?