If you want to poke everyone that has poked you, then you have to visit facebook.com/pokes on your web browser to poke them back.
You’ll see the list of friends and Facebook users that have poked you.
Mind you, friends of friends can poke you. Hence, you shouldn’t expect to see pokes from friends alone.
Please share this article with friends on Facebook so they can also find out where they can find their pokes and also to know what pokes means on Facebook.