<human>: Could you distill the essence of the text into 1-3 sentences?

I am 23, and have been with my girlfriend since High school. We have been together for 6 years. We have both never been with someone else. We have come to a point where it seems logical to settle down and live together. We have both finished university which previously forced us to live 100 miles apart. It seems logical to go live together, but I don't want to. The underlying reason is that I still feel too young to settle down. If I settle down with her I feel like I have missed out on an important part of being young. I mean the flirting, dating etc. It seems fun to me and a loss to have missed it. 

I am scared if I break up with her I will never find someone as nice as her again. 

Issues:

**On the positive:** a part of me never wants to lose her, I love her and truly care about her.  I would miss so much of what we have together.  She is truly the sweetest person I have ever met. 

**On the negative:** We are both very different people, and I am sometimes scared we both could be happier with someone else more like ourselves. The only reason that it has worked so far is because we are both nice people and really respectfully towards each other's differences. We both dislike each other's hobbies and profession.  Although it isn't a major issue so far it would be nice if we had at least one similar interest. We never had one where not someone needed to compromise. From holidays, clothing style and dinner choices, we have never agreed ever. 

I am also scared that our desired lifestyles are so different that we will break up around 30 anyway. I would prefer to be single at 23 than at 30. She desires a simple life, 9 to 5 job, 3 kids and a house near her family. I desire an as exciting life as possible, living in different countries, working in different industries etc.
<bot>: I feel like I have missed out on being young and single if I settle with my high school sweetheart. Should I break up or should I stay?