This is so annoying when it happens to me. It tells me that it’s time to practice some more of the basics for a while. It’s when your pick gets caught on a string on the upswing. It brings your break to an abrupt halt until you get the pick extracted. What’s even worse is when the string not only gets caught on your thumbpick, but also finds its way up under the edge of the upper part of your thumbpick. I’ve also had that happen.
Even that is not the worse, though. Imagine if that string not only got caught up under the thumbpick, but it pulled it all the way off as you pulled your thumb away; leaving it there to dangle in abject humiliation on a now silent string. Horrors!