When you smell something, that thing is actually inside you. You can say you smell a flower, but what you’re really smelling is some volatile molecules from the flower, and when you smell them they’re already inside your nose.
Likewise, when you hear, the sound waves must have already entered your ear.
Even when you see, what you really perceive is light hitting your retina, which is inside your eye.
But when you touch something, that thing is still outside of you. Technically, can also be said of taste if you lick something, but then there’s a strong likelyhood of some molecules of the thing entering your mouth as a result.
True, but the pressure wave is what is being perceived when hearing, light is what is being perceived when seeing, I never said what was being perceived had to be matter. In the case of touch, some molecules may enter the skin, but that is not the cause of the sensation. Even if you imagine an perfectly hard, smooth and clean surface that sheds no molecule, you should still be able to feel of you touch it.
However, I thought about it after making this post, but there also is a small amount of kinetic energy entering you when you touch something, and that may be what triggers your nerve… So I guess even in the case of touch, it remains true that you can only perceive something that’s inside of you.