I believe people should be on their own for a bit before committing to another person to find out who they really are. Having said that, my husband is the only guy I dated, we knew each other online for four years, met in person twice and he moved out here seven months later, we where married five months after that. Would have been three if his parents could have came earlier! I was 21 : ). It really depends on the individual, at 18 I knew if he ever moved into my area we would make it work. Apperantly, I found out recently, he told my Mom for four years that he was going to marry me!
: D My mom actually masterminded getting him from NY to Washington State for a visit to see how we hit it off in RL (real life). His parents had no clue until my Mom called them! They toned him out when he talked about his gaming friends.