Not weird however I do love birth stories I certainly wouldn't be asking someone if I didn't have to (as a midwife can't avoid it often) perhaps for a woman people ask as its something a large amount of us have done as adults regardless of our age (ie 20's to 100) maybe its something we all feel like we have in common although some of us have an easy time and others have a horrible time. If you don't feel comfortable talking about it and it is very private then I would tell them its none of their business or find a way to make the person realise its not a topic they should be asking you about. Unfortunately its probably something that regardless of how old your children/child is your going to be asked.