Take all reasonable advantage of that which the present may offer you. It is the only time which is ours. Yesterday is buried forever, and to-morrow we may never see.
[T]omorrow is a new day. You shall begin it well & serenely, & with too high a spirit to be cumbered with your old nonsense. This day ... is too dear with its hopes & invitations to waste a moment on the rotten yesterdays.
You have it now and that is all your whole life is; now. There is nothing else than now. There is neither yesterday, certainly, nor is there any tomorrow.
It is not enough to want to make the effort and to say we'll make the effort. We must actually make the effort. It's in the doing, not just the thinking, that we accomplish our goals. If we constantly put our goals off, we will never see them fulfilled. Someone put it this way: Live only for tomorrow, and you will have a lot of empty yesterdays today.
With the mistake your life goes in reverse. Now you can see exactly what you did Wrong yesterday and wrong the day before And each mistake leads back to something worse.
..there is nothing worse than the feeling that no one cares whether we exist or not, that no one is interested in what we have to say about life, and that the world can continue turning without our awkward presence. I began to imagine how many millions of people were, at that moment, feeling utterly useless and wretched—however rich, charming, and delightful they might be—because they were alone that night, as they were yesterday, and as they might well be tomorrow.