Sort of. It's kind of like saying "Everyone knows how to give a massage." It's technically true, in that most people who speak English know what the word means, and most people can sort of do it, but speaking as someone who doesn't do it very well, it's definitely still a skill.
I think that everyone knows how to tickle in that limited sense mainly because 1) people know what the word means and 2) it's something that most people learn how to do in childhood. They learn to associate the word with the action and the sensation because other people do it to them, they see it done, and they do it themselves as kids.