Because there may not be a tomorrow.
Last night I lost a very dear friend, stupidly young. If you are of a praying turn of mind, you could pray for her wife and their two very young children.
In the ten years I knew S, we met in person all of three times. It was one of those internet friendships that aren't really proper friendships, that don't count - and all over the world today there are people mourning S, as we realise that never again will we find one of her emails in our inbox, never again will we have the privilege of reading her words. She was always wise, always generous, always kind. She personified grace. She knew more about more things than anyone I've ever met, and all her knowledge was for sharing. My shelves are filled with the books she recommended, and propped up amongst the clutter are her postcards.
That which we give to others is not lost. The world is not a poorer place for her passing, it is richer because she lived. But we bloody miss her tonight.