I married a beautiful woman with a "weird uncle," whom she told me had taken them caving, and rappelling when they were kids. I would get invites to go caving with him at family get-togethers for a couple years. Finally, I took him up on it, and joined him on a trip to his cave property. It was a short cave maybe 1000' long at most, but i followed him as far as he was willing to lead me, which was up to a muddy slope before a pit. "No more without being clipped in" he told me - and I was quite comfortable the whole time.
We enjoyed a sip of The Macallan, and some cheap cigars before leaving the cave. After a couple more trips, I was hooked.
A little more than a year later, we have cave gear for the family - my 6 year old son, and 10 year old daughter as well. My wife and I have taken SRT classes and have a full vertical kits now.
But the highlight for me, has been caving with my 10-year-old daughter, who is just an animal in cave. She's done some pretty challenging 6-7 hour trips, and is eager to tag along now.