Isn’t it crazy we don’t have two hearts ♥️ ❤️ ?

Question

Then if something bad happen to the first one the second one can kick on like a generator 

Answer 1

well   spare parts would always be nice .

Answer 2

I don't see any particular advantage to that, although I've had two heart operations.  I was found to have been born with only a bicuspid aortic heart valve.  That affects about 1 man in 145 or 1 woman in 250.  If you have Celtic descent, that increases to about 1 man in 70 & 1 woman in 145.  In 2015, I had to have the valve replaced.  After about 15 months, it failed due to a biological contamination.  I had to have the new valve replaced in 2016.  

Medical science can do a lot of very complex things to repair damaged hearts now.  

Answer 3

We are not "Time Lords" from the planet Gallifrey.  One heart is enough for most people to last their entire life.

Answer 4

I have four.