Cooking pigs' trotters is an awesome process that I think everybody should try at least once in their lives. Mind you, it's not for the faint hearted, so if you're at all squeamish then it's probably best you avoid it.
It's really fascinating to watch them change as they cook. If you've ever had those Chinese teas with the whole flower buds that open as the tea brews, cooking trotters reminds me a little of that. What happens as they boil is that first everything swells. And then at some point, the swelling becomes too much or the skin tightens too greatly in the cooking process and bursts open, revealing a mass of flesh, bone, ligaments, and cartilage. At this point the trotter is still relatively whole, but the longer it cooks, the more it bursts open and gradually comes apart. Eventually you're left with a mass of very loosely-connected bones and cartilage floating in the remnant of skin. The toenails may still be attached, or they may be floating loose. If you go to pick up the trotter, it disintegrates entirely. I never would have guessed that there were so many tiny and intricate parts going into that structure.
It's a very visceral feeling, I found that I felt rather intensely just how mortal I was as I became extremely conscious of my own body being made up of bones and cartilage encased in skin like that.
So it's on both counts that I think that everyone should try cooking a pigs' trotter: firstly, the fascinating deconstruction process, and secondly, the intensity of feeling completely mortal. But not if you're squeamish.