Can You Ever Know For Sure ?

What do you feel at this specific moment? Happy, sad, in love ... etc.

Can you ever be sure that this is how you feel? I mean, how you can know that it isn't your mind manipulating you.

I am a person who believes in the power of mind, and how it can control many things. So, whenever you feel anything, how can you be sure that it's really your feeling and not what your mind wants you to feel??