Adapted from a recent online discussion.

Question: My boyfriend says that, as of now, he doesn't think he'll want to have kids. (We're both in our early 20s.) I know I do want kids, and I know "Eli" would be a great husband and father if he gave himself the chance. I think he might change his mind, and he acknowledges that indeed he might.

We love each other, share the same values, and are really great friends. How long should I wait to see if Eli actually will change his mind? One year? Five years? What's realistic? I want this to work, but I don't want to wait forever if the same deal-breaker is at the end of the tunnel.

Answer: If staying with him is something you equate to "waiting," then it's probably better to break up with him now. The thing to look for is a relationship that feels like living your life, no matter what stage of your life you're in.

People are ends unto themselves. Once you've started seeing them as a means to an end, you can no longer be sure you like them for who they are versus what you envision getting. The former is contentment, the latter is time-release disappointment.

Q: I've been in a relationship for four years with my girlfriend. We are discussing marriage, and she wants kids, but I don't really know what I want. She is convinced I'll change my mind in a few years. I want to build my life with her but I'm worried that in a few years I won't change my mind, and then what? Is it better to end the relationship now or wait and see what happens?

A: What are the chances? (See above.)

I'm worried that your girlfriend believes "Oh, you'll change your mind" is a sound way to approach her life.

Since you don't share her optimism, I think you need to be absolutely clear with her that you can't enter a marriage on those terms. As in: "You're convinced I'll change my mind, but I'm not. I need for you to take seriously the possibility that I won't want kids, and we need to talk about what you'd want to do if I realized that, say, five years into our marriage."

For your part, I think if you are leaning against having kids, then you need to say that instead of representing yourself as not really knowing.

Q: When I was in my last year of college, the girl I was "serious" with was 100 percent sure she would never have kids. I always knew that fatherhood was a certainty for me. Eventually, after graduation, the relationship died. Having kids or not was definitely one of the main causes.

That was 25 years ago. Today she has three children, and I've been married to the best woman in the world for 15 years but we have no children. Life takes you where it will if you let it.

A: Yep. That first step is a doozy, though, isn't it?