For me that means being deeply immersed in my hobbies, and traveling the world and being active etc. All that I expect to change are toning down the active activities to things that an older body can still manage, like skiing, scuba diving, hiking etc.
I can't see ever wanting kids or even coming close to that as I haven't even ever had a desire for a partner yet.
I would argue that you often have no idea what your future self will want. This is why advice from elders, parables and traditions are valuable. Ignore what they suggest at your own risk.
There just isn't a single thing about a significant other or kids that I have ever even thought about wanting.
It just seems very weird to me to do a complete 180 and pursue all these things that I have 0 interest in pursuing. I wouldn't even know how to begin. Forcing myself to get a significant other etc just seems like a bad idea and at the very least a big disservice to whoever I end up pursuing.
My only suggestion is try to consider what you may want at 50, 60, 70 and how you have a short window in your 20s and 30s to have children.