We don't care

We only have one life, so why do most of us waste it.
We live by the same rules everyday and never change.
We only have this one world and we look at it likes its nothing.
Trees the earth. What happens when it's all gone? 
Would we miss it? Or would blow it off and say we don't care? 
And of course we only have one heart and that heart can only
be given to one person.
But how come we give it to everyone who looks at us twice? 
We watch it get broken all the time.
So I ask you what happens when we die and we think of the things
that we would have done differently.
Would we have lived our lives to the fullest? 
Would we have taken better care of our earth? 
And would we have been more careful who we gave our heart to?