Unless I can figure out how to, or someone teaches me how to get rid of the amnesia humans are born with and remember all incarnations, I can't answer that.

My cop out answer is that since the sum of all consciousness is 1, then the number is "all of them".

A finite infinity of them, if you understand how infinities work.

Not enough to leave me happy. ATM I sometimes look forward to the next but i'm no one so dramatic.

None. I came from fragments of combinatory chemicals and will liquify and return to dirt. But while I'm here I get you folks for company, so make it worthwhile.

I forget what I ate for dinner the night before so remembering another life would be impossible for me, past is gone so it doesn't matter in this world now just the lessons learned.

I try not to remember them all. At one point the memories were overwhelming so I asked for a decrease of information. When you are first learning to receive information of that type it can be an overload. It's like using a muscle just like everything else.

Essentially, I asked that I only receive information "For my highest good" so that any "spidey-sense" of a psychic inclination is to help with an activity directly at hand. That being said, I recall many past or alternate lives.

They are not memories from start to finish like a movie, they are more like glimpses of moments. Usually those moments have an immediate application to help understand what I am experiencing now. Maybe this resonates with you or it doesn't. I don't really care what other people think at this point