And while dwelling, as I do, upon the brevity of all things, the fleeting and transitory nature of our lives - our thoughts, feelings, possessions, friends and loves - here is a much collected poem by Percy Shelley. We cannot keep a hold of what we want or desire and if we try, it passes like sand through our fingers.

'The flower that smiles to-day
To-morrow dies;
All that we wish to stay
Tempts and then flies.
What is this world’s delight?
Lightning that mocks the night,
Brief even as bright.

Virtue, how frail it is!
Friendship how rare!
Love, how it sells poor bliss
For proud despair!
But we, though soon they fall,
Survive their joy, and all
Which ours we call.

Whilst skies are blue and bright,
Whilst flowers are gay,
Whilst eyes that change ere night
Make glad the day;
Whilst yet the calm hours creep,
Dream thou—and from thy sleep
Then wake to weep.'