Statistically, indeed, we are unlikely to marry a girl/boyfriend in teenage. However, we should try out best to make the relationship last as long as possible. Thus, we should keep thinking about marriage in the future. I believe that such attitude helps relationships to work better for both of them.
You are pressured to marry and have kids. This is not the 1800 where people married young because they died before 40.
You are suppose to see how each other is. So many teens want to marry the first person that asks them out. And then they get married and find out that they hate each other.
Marriage is something that people do not understand. They want to live in some fairy tale full of passion but get slapped by reality that they picked a loser.
That cute girl might be a lazy girl that wants to shop all day. Or that perfect man is a wife beater and chronic cheater.
People are more thoughtful in buying cars and picking food than they are picking spouses. You will be bitter as your perfect spouse gets out of shape and is just agony to be around. So you do you and hitch yourself its your life
Just because you love or care for someone your seeing does not mean they share the same affection. Fixating on marriage would just lead you to heartache. Professing love or talking about marriage to your boy/girlfriend too soon will likely freak them out and make the rest of your relationship uneasy if it doesn't come to a crashing end. I'm not saying you should abandon the idea, Just try to keep some control over your own emotional attachment. If things don't work out for some reason, You won't be as heartbroken. Thing is, The longer it lasts, The more likely that both will fall in love. Till then, Enjoy the time you have with them.