Gf Says No Kids = Loneliness?

[goddamnit]

I told my girlfriend I don't want to have kids. She told me I'm gonna be lonely without a family as time goes on. My friend said his mom told him this too.

I guess that in high school, you don't need your own kids to not be lonely? But as you get older, that changes because friends have their own families? I miss simple truths in life, so someone please explain this to me.