I'm not much into caves mainly because there's creepy crawly things in there. I've been to Mammoth Cave a couple of times and the overall trip was enjoyable. I'd never go in search of an abandoned cave to explore.
As a teenager some friends and I would gather at caves we’d find and explore them. Of course, not all of any particular cave was deeply explored, however, we would explore good portions of them. (sinkholes included)