General

Explaining a sense to someone who doesnt have it

So, out of all of the senses which would be the hardest/easiest to explain to someone who doesn't have it and has never had it. Assume you wouldn't have to learn a new language to talk to them.

I feel like vision would be the easiest, however color would be hard to explain.
As for the hardest, everything else.

As for why I think vision would be the easiest, I would explain it as being able to know the physical location of something by facing your eyes towards it.