The feeling when your heart overflows with the joy of living and being able to just be free and have fun.

Briefly, "the realization that each random passerby is living a life as vivid and complex as your own." Originally from the Dictionary of Obscure Sorrows, which has a lot more beautiful neologism definitions like this you might enjoy.

it means that you are very exited about things and have no bad feelings about anyhing that will happen to you!

A feeling of contentment and peace, like you don't need anything else.

How you make me feel.

what everyone wants to be without the aid of mind-altering substances

A chemical reaction