It took both some growing up and beginning to get serious with someone to come to this conclusion. But it’s far from naive and very much legitimate to begin to plan a long future with someone once you two become intimate, exchange feelings/emotions, and are building a relationship. Why because at a certain age you start looking at your relationships as ones that will be long lasting, sincere, and practically forever. You don’t continue to go around getting in relationships that will be momentary or insignificant. You look at relationships for commitment, support, and stability.
So begin to plan for the future with that person. Start saving money for the next stage of you two together. Whether it be for the wedding, that first house or apartment, the future of your children; start to build more than a foundation that has common likes and similar favorite movies and food. I understand now, you may not go into it with that thought that THIS IS THE ONE, jumping and shouting. But you’ve begun to invest time and effort, so you know you see a future with this person. As that invest builds you get that thought YEAHHHHH THIS IS THE ONE, maybe not jumping and screaming but it’s there and you embrace it.
But here’s the kicker, SO WHAT IF YOU TWO DON’T LAST, AND YOU END OF BREAKING UP. You haven’t lose, by far you haven’t; you’ve gained one of the greatest things one can have in life. You’ve gained experience and an outline/a framework for the next relationship. You know that in your next relationship it’s going to be about more building, more establishment, more complex foundation. You’ve already had the groundwork laid from a previous relationship. So it’s not starting all over, it’s picking up whatever pieces you need to and get going from there.