The Computation by John Donne

For the first twenty years, since yesterday, 
I scarce believed, thou couldst be gone away, 
For forty more, I fed on favours past, 
And forty on hopes, that thou wouldst, they might last. 
Tears drowned one hundred, and sighs blew out two, 
A thousand, I did neither think, nor do, 
Or not divide, all being one thought of you;
 Or in a thousand more, forgot that too. 
Yet call not this long life; but think that I      
Am, by being dead, immortal; can ghosts die?