The Importance of Conscious Experience

A person exists as long as future conscious experiences are probable for that individual. When future conscious experience becomes impossible for that individual they lose the ability to have a conscious. So my point would just be then a person if a person stops existing when future conscious experience become impossible why can't we say a person exist as long as the future experiences are possible and a person starts existing at the first moment those experiences are possible? I'm actually being generous because the symmetry would not be improbable it'd be possible.