Words of Wisdom: what personal mantras do you live by?

Despite the fact that I have a subscription to O: The Oprah Magazine (it's good, I swear!), I don't think of myself as the sort of person who likes or needs little sayings to get me through the day. I don't want to get up and declare "Every day in every way I'm getting better and better!" or any other time-honoured inspirational mantras. Not only do I hate the word "inspirational" (it sounds so sugary sweet), but I don't want to be someone who tries to boil down thoughtful wisdom to a snappy sentence.

But although I may not want to be that person, it seems that I actually am, because there are a few lines, some from books, some not, that have stuck in my head and spontaneously popped up in my mind over the years to give me real comfort when times are tough. And the ones that I think of the most, and the ones that have helped the most, come from rather unlikely  sources.

Most people don't think of Milton's epic 17th century poem Paradise Lost as a self-help manual, but a few of its lines are, well, kind of uplifting. Like "What though the field be lost? All is not lost." I encountered this line in the segment of the poem that I did for my Leaving Cert in 1993. It's said by none other than Satan, who, to my 16-year-old self's pleasant surprise, turned out to be pretty charismatic and entertaining.

While I should possibly be worried that I'm comforted by something said in a poem by the devil after being cast out of heaven, I've found myself thinking of that line after various setbacks ever since I first memorised it just in case I had to quote it in my English exam. I can't remember whether I answered a question on Paradise Lost in my Leaving or not, but those supposedly demonic words have encouraged me now for nearly twenty years.

Another epic, Neil Gaiman's graphic novel series Sandman, may not seem to have much in common with Milton, but it does – and not just because the Prince of Darkness turns up there too, in a rather different form. It's another work that's given me a line to live by, in a story about a boy stuck in his boarding school for the holidays, a school that's suddenly full of the teachers and pupils who died there. They're all trapped in their own hells, but when the boy dies there himself, of hunger, cold and neglect, he and another dead pupil refuses to go along with the rules.

They walk away from the school, and one says to the other, "I think maybe Hell is a place. But you don't have to stay anywhere forever." And off they go to have adventures. I first read this story twenty years ago, and the words "You don't have to stay anywhere forever" have stuck with me ever since - the awareness that if I do find myself in a bad situation, happens, I can always choose something else. It's an idea I still find liberating.

And I'm almost ashamed to admit the last words of comfort - not because of who said them (the singer-songwriter Aimee Mann – nothing particularly embarrassing about her) but about where I read them. Because it was, yes, in O Magazine. In an interview, Mann said that once when she was stressing over some possible disaster, a friend said, "If it's not happening now, it's not happening". And, you know, it's true.

Ever since I read that, whenever I find myself freaking out over something that might happen (but probably won't) or even something that did happen (but which wasn't a total disaster really), I tell myself, "If it's not happening now, it's not happening. Everything's fine. Stop worrying about something that doesn't exist". And I always feel a bit better.

So what about you? What words of wisdom do you live by? Or do you not feel the need for any personal mantras?