My story starts in the northern Galapagos Islands, under 50 feet of water and a big school of sharks. I'd been scuba diving with a group of friends for about a week, and it had been glorious: manta rays, whale sharks, penguins and, of course, hammerhead sharks. Today's dive was particularly tricky. The surge was terrible. You had to have your camera rig tight in and your arm out, because the surge kept throwing you into the rocks while you're scanning up for that beautiful photograph. It was going OK, until ... not OK. Something was terribly, terribly wrong. I pulled my hand back, and I had long, black sea urchin spines all the way through my gloves, which meant all the way through my hand. Now, this is bad. I mean, obviously when you have something all the way through your hand, it's kind of bad anyway, but in this case, sea urchins have a venom on them that, if you've ever tangled with them, you know that a sea urchin spine in you gives you horrible, painful inflammation. But that wasn't even topmost in my mind at this point. This did not look real. I could not believe that this was my hand. Now, in a crisis, I tend to disassociate into, like, little scientists, and I start talking very analytically. All analysis was gone, adrenaline brain kicked in, and I just yanked the spines out. I don't remember doing it. I just remember thinking, "I can't get my glove off with these in here." I do remember taking the glove off and a big plume of black coming up in front of my face. And biologist brain now shows up and starts freaking out. "How could all that toxin have gotten into that wound already?" Well, physicist brain then shows up and very calmly explains, "No, no, no, we're at 50 feet, red wavelengths are attenuated. That's blood -- not black. And sharks. So what are you gonna do?" Well, I cranked my cummerbund down really hard over my hand, and I simply swam away. "Let's let that big old cloud of blood dissipate a bit before we have to surface through all of these sharks." So when I did surface, my warm-blooded-mammal brain was in an absolute gibbering panic: "They don't feed when they're schooling. They don't feed when they're schooling. All the way up." And they didn't. So apparently, they have read the same books that I have. (Laughter) Now, it turns out, when you've been stabbed with sea urchin spines, and you're two days away from any medical help, the thing that you've got to do is, unfortunately, cook your hand. So you put it in water as hot as you can stand, and you keep adding boiling water until you think you will go absolutely insane. Now, it worked -- the hand itself did not work so well for several weeks after that, but eventually, fine motor skills returned. All except for one spot, that stayed stiff and painful for weeks after the other things had gotten better. So it turned out, I'd broken off a tip of the urchin spine in the joint itself, and that's why it wasn't getting better. So the orthopedist says, "You know, we should get this out. Nothing too urgent, not an emergency." So we scheduled a small surgery for a few weeks out on a Monday. And on the Friday before, I broke my pelvis in a horseback riding accident. (Laughter) Yeah. So we kind of postponed that surgery. My broken pelvis and I were now facing six weeks on the couch, and I would have gone absolutely insane if it hadn't been for my friends. Spontaneous parties broke out at my house every night for weeks. I was fed. I was entertained. It was great. But that kind of enthusiasm is sort of hard to sustain over the long term, and eventually it petered down to just one friend, who would send me jokes during the day and come and keep me company in the evenings -- someone I got to know a whole lot better during this period of convalescence. And when I was finally pronounced well enough to do weight-bearing activities, we loaded a telescope in the car and drove up into the mountains to look at the Hale–Bopp comet. Yes, we are geeks. And got caught in a landslide. (Laughter) I know -- like, really? No. Just kidding. (Laughter) No more disasters. No. Just the opposite, in fact. That was 21 years ago, and for 19 of those years, I have been married to that marvelous introvert who never in a million years would have approached me under other circumstances. We have a wonderful 14-year-old daughter, who did all my illustrations. (Cheers and applause) Yeah. So, pro tip: apparently, nothing makes you sexier than needing a walker on your first date. So this isn't a story about piercings or sharks or boilings or breakings. It's a love story. It's a love story with a funny little epilogue. Now I was weight-bearing again, I could reschedule that surgery, get the spine out. But I didn't need it anymore. Turns out, when you break a bone, your body scavenges calcium from all the bones in your body -- and from the little sea urchin spine that you happen to have lodged in the joint of your finger. So yes, my pelvis is now part sea urchin. (Laughter) So to biology brain, physicist brain, adrenaline brain, warm-blooded-mammal brain, I get to add "urchin brain," with all of the superpowers that that confers. You don't need to worry, though: that I am not fully human is one of the things that my family loves the most about me. (Laughter) Thank you very much. (Applause)