Am i alive?

are you really alive ?yes you say well why? the first thing i think of is i breathe therefore i am alive but what about beings that live without air? ok so how bout if i think i must be alive?
how do we know other people think or plants or animals through perception of our senses it that what makes us alive? movement of a rock across death valley is the rock alive? or just the desert floor it rides on? we have not got enough information to really know! crazy as that seems!