A guy on a bus is sitting next to another guy. Guy #2 is fondling what appears to be a small rock covered in blue paint. Guy #1 can't contain his curiosity, and says to guy #2, "What's the rock for?"<p>"Keeps away tigers."<p>"Oh, come on now, that's just silly. That's just not possible."<p>Guy #2, with a sly smile: "Seen any tigers lately?"<p>I've been wearing a mask in public since the pandemic started, and taken all available vaccinations, and I've never caught Covid. Coincidence? I don't care, works for me.