If it were an electric appliance question, I'd ask, "Did you plug it
in?" So don't be insulted if I ask you: Did you peel the paper off the
sticker to reveal the adhesive? Did you try to put the sticker on
freshly oiled or skin-creamed skin? You didn't try to lick the sticker
before applying, did you? Do a couple of insulin droplets drip onto
the sticker surface from the catheter-inserter before applying?