If you drop it, pick it right back up. Believe in the three-second rule: no germs attach to it as long as you pick it up within three seconds. It helps if no one else sees you do it, because sometimes there can be a lot of judgment ("You're not going to put that in your mouth after it's been on the floor, are you?"). Well, it depends on the floor, doesn't it?
If it's the floor of a subway station, I'm with the critic: don't put it in your mouth. That's not a floor I'd trust. The germs on that floor never heard of the three-second rule, and if you drop something they're all over it like white on rice, faster than you can shake a stick at them (or in two shakes of a lamb's tail—whichever is quicker).
Back to that subway floor. No, we've finished with that one, having agreed that if you do pick it right back up from the subway station floor you put it right straight into the trash, where it will touch no one's lips.
Other floors? Are there floors you can trust? Lorna comes to shine up my house every other week, but in the days before Lorna started coming I would leave my kitchen floor unmopped for longer than most people would. Longer than I care reveal publicly. The three-second rule would apply for the first few weeks after I mopped it, but I'd reduce it to the two-second rule after a month. And the one-second rule after that. And then we'd reach a point where it would be better not to drop anything at all on the floor because the floor was alive and would make quick work of whatever it was you had dropped. You'd want to say "drop it" to the floor as you might to a dog, but you knew that whatever you dropped at that stage was beyond help. Leave it.
And then I'd mop the floor, grudgingly, and the cycle would begin anew.
But now Lorna comes and the three-second rule is a safe measure. Other floors? You'll have to tell me about your own floors. Will the three-second rule apply at your house?
What about the street? The sandbox? We're supposed to eat a peck of dirt while we're alive. I think the idea is to inoculate ourselves by ingesting the very germs we are so frightened of. Brush off that lollipop and put it back in the toddler's hand. (More to the point, why is that toddler eating a lollipop in the first place?)
Ice cream cone? Don't bother picking that up. Just let it melt on the sidewalk, a monument to a child's unhappiness, a booby trap to the unwary walker (especially the fools who go barefoot on city streets). I've always wondered about ice cream cones on the sidewalk within ten feet of the ice cream shop. Did the poor kid get a replacement? Or were the parents the stiff-necked, all-rules kind who said, "It's your own fault. Next time be more careful!" and was the child forced to watch through her tears as her siblings flaunted their own double-dip cones: chocolate mint paired with rocky road.