Well if you're dating during the time people still marginalize you as a 'child,' then it's only for practice anyway.
Time consuming, money consuming, tiring, emotional problems, arguments, giving attention, breaking up, asking to date in the first place, not seeing each other for a long periods of time, being devoted, friends taunting you cause they don't have girlfriends etc.
Seems like a lot of hassle and trouble just for something temporary. I know you might say it's "worth it for true love loel1!" but that's like saying it was worth having kids. People who say that ironically are usually ones who haven't had any intimate relationships or have not had children and that's just their philosphy based on limited perspective and insight.