I bought "A Guide to the Good Life: The Ancient Art of Stoic Joy" back in 2011. Soon after, I'd read most of it, then set it aside. Now I've finished the book.
It's an interesting look at ancient Stoicism from a modern perspective.
The author, William Irvine, is a Professor of Philosophy who, unlike most academic philosophers these days, believes philosophy should have something to say about how we should live our lives -- which is how the ancient Greeks viewed philosophy.
Here's some passages regarding the past, present, and future that I like. Somehow I'd never really grasped that while the past is out of our control, so is the present. Only the future is uncertain and potentially controllable.
We should be fatalistic with respect to the external world. We should realize that what has happened to us in the past and what is happening to us at this very moment are beyond our control, so it is foolish to get upset about these things.
...In your practice of Stoicism, you will also want, in conjunction with applying the trichotomy of control, to become a psychological fatalist about the past and the present -- but not about the future.
Although you will be willing to think about the past and present in order to learn things that can help you better deal with the obstacles to tranquility thrown your way in the future, you will refuse to spend time engaging in "if only" thoughts about the past and present.
You will realize that inasmuch as the past and present cannot be changed, it is pointless to wish they could be different. You will do your best to accept the past, whatever it might have been, and to embrace the present, whatever it might be.
Here's what the above-mentioned "trichotomy of control" means.
According to the Stoics, we should perform a kind of triage in which we distinguish between things we have no control over, things we have complete control over, and things we have some but not complete control over; and having made this distinction, we should focus our attention on the last two categories.
In particular, we waste our time and cause ourselves needless anxiety if we concern ourselves with things over which we have no control.