When you interact with the world around you, have you ever noticed
something? No matter what your eyes see, or ears hear, or tongue
tastes, or nose smells or your hands touch, it is your mind that
ultimately provides you the information. If you are asleep, or
unconscious, no matter what your eyes see or ears hear, and so on,
you will not be aware of anything! So, it is the mind that sees, or
hears, touches, tastes, and smells. 

That being the case, how do you
know that what you see, or what you hear, or what you touch etc.
actually exists out there?