I went to buy some band-aids at the resort boutique this week and had to sign a receipt to put the charge on my room bill. The lady behind the counter didn’t look twice at my signature, but I noticed something that has become a bit of a habit: when in a rush, my signature has become a rudimentary cursive“S” with a bunch of squiggles after it—a pretty consistent shape of squiggles, but illegible nonetheless—rather than the carefully crafted first-initial-last-name stylization of curs...