If you have ever read The Five People You Meet in Heaven, do you know what the theme would be? I think it could be something like take the chances you get in life and use them because life isn't fiction, it's real, and sometimes you don't get a second chance. OMG, I have no idea what I'm talking about.....please help me

This has been stated before, in various phrasings. One of the most famous ("carpe diem"is in this poem by the Roman poet Horace:
http://en.wikipedia.org/wiki/Carpe_diem

=)