Grandfather clocks

Two grandfather clocks tocked quietly in a corner:
‘You know’, said one, ‘this heart of yours is your most precious possession. The piece of you already in Heaven.
Look inside - smile!
There is nothing more beautiful in the world.’
The other said:
I feel like an elastic band
Stretched in all directions
Ready to snap.
‘Then throw away the elastic band’, replied the first
‘It cannot be you.’
The shopkeeper heard them musing, and chuckled to himself:
We understand ourselves of yesterday
Today, we are a total mystery
Our selves of tomorrow
We cannot even imagine.