I’m going to answer the bit specifically about you, (rather than the larger, generic question), and my answer is from my own experience… (Please don’t read my answer as saying ALL women or ALL men are this, that, or the other.)
Have you come across the situation (perhaps you’ve noticed it with your father?) where letting the man think that something is their idea will make it more likely to happen, and more likely to go smoothly? Some women are masters of this art, because they have partners that work very much in this way. You could call it a game, but it’s more a tactic for leading an easier life. Women who find themselves in this situation can either find it really frustrating and annoying, or they can think “c’est la vie” and crack on with it, still ultimately getting things their own way anway.
There will be things that men do for an easier life too, I’m sure.
Accepting and embracing this knowledge, that men think and operate differently from women, is very helpful in getting on in relationships. You just can’t expect the opposite sex to automatically think the same way as you about things, no matter how much obvious sense it makes to you. Particularly when it comes to approaches to dealing with things (say, problems with a friend or putting together that Ikea cabinet), or when it comes to approaches to life plans.
At your age you would, these days, be considered young to get married. That doesn’t mean you’re too young to be wanting it for your life. (It doesn’t even mean that you are too young to get married, but I know that’s not what you’re asking about.) But remembering that guys are different to gals, it is very unlikely that you will find a fella that will feel comfortable even contemplating the possibility of future marriage to anyone at your current age. That is completely different from them being people who will choose to never get married. It’s just so far from their thoughts right now. And that’s okay. It’s every bit as okay as you wanting to get married and settle down and have kids in the future (whenever that is).
So, how do you move beyond this? You just don’t mention it. In the same way that guys like to think an idea is theirs, even when you’ve planted it there, and as a result you get an easier life… In the same way as this, you accept that the fellas (in question) are not capable of dealing with this topic yet, but that that is different from what they may or may not actually want. You don’t let it rear it’s head, because it doesn’t get you to where you want to be. You bide your time. You don’t focus on it. You accept life as it is, knowing what your overall life plan is. The point at which you want to be married NOW, and having babies NOW – that is the point where you need to have the conversation no matter what.
I’m not saying tell untruths, or mislead. If the topic of marriage or babies comes up (NOT from you), then say, “yeah, I definitely want that some day”, then let it drop. Obviously don’t stay with someone who says from the outset that they never, ever, want the same things as you. But that’s common sense, right?