In darker times, it can be the simple, almost imperceptible moments that can change a life as well. That moment when you notice someone repeating themselves just once too often, saying something which seems at odds with what they think... the diagnosis may be the momentous thing, but somehow it was those days you just began to wonder when you knew by instinct things were going to change.

The most famous stage direction in Shakespeare: Exit, pursued by a bear, is found in one of my favourite plays, The Winter's Tale. It's a story of rebirth and forgiveness and life-changing experience. I've never been 'pursued by a bear', unless you count the love of Paddington and Winnie the Pooh which has lingered since early childhood.

When it comes to thinking about life-changing experiences, as the new year gets into its stride and we start to think about how it will turn out, I don't quite know where to start.

There was the time, on my eighteenth birthday, that I was doing some reading ahead on Shakespeare to prepare for my final year at school, when there was a car bomb outside Belfast Central Library, and I argued with the librarian about evacuation when just five more minutes would have let me finish my notes. There was the day, about twelve years earlier, when I'd faced my fears in the same city centre when my parents took me to meet Santa Claus, whom I was utterly convinced was a terrorist. I survived. There were the times I went off on European or Irish tours with youth orchestras for weeks on end, sampling life without parental supervision and assistance, trying out my languages and making lots of friends despite my shyness. There was striking out on my own to go to university in England and to try out teaching for a year in France - experiences which developed my brain as well as making me certain that, much as I'd ridiculed the possibility while at school, I was going to have to follow the irresistible draw towards teacher training and the classroom.

When we think about life changing experiences, we tend to think about the big moments. The time we only just survived - the illness, the car crash, the moment we were approached by the strange man in Charles de Gaulle airport during a snow delay and asked if we would put un petit pacquet in our bagages. True story. I said non.

But surely life can change in the tiny moments too: the instants we hardly even notice. Searching for a seat in an over-crowded staffroom resounding with first-day-of-term chatter last week, I was forcibly reminded of what I used to do in my first year at primary school, following the few girls I had latched onto around until they settled on a suitable place to sit, then finding myself a corner which they seemed to find acceptable. My Mum got a phone call about telling me to be more assertive: clearly it's a new year's resolution I might still need to consider. It's those tiny, insignificant moments which really change or shape a life. Those moments of decision, indecision - those moments when we reach out to someone and it just works, and a lifelong friend is made. That day 20 years ago or more, when I started talking to a friendly person over coffee at rather a dull teacher in-service training course, gradually noticing that he told good stories and had a brilliant sense of humour, little suspecting that this would turn out to be my husband. There was no lightning bolt that day - just a certainty that we wanted to talk to one another again, and again, and again.

In darker times, it can be the simple, almost imperceptible moments that can change a life as well. That moment when you notice someone repeating themselves just once too often, saying something which seems at odds with what they think... the diagnosis may be the momentous thing, but somehow it was those days you just began to wonder when you knew by instinct things were going to change. We might all have the day when we face our own demise: for me, it was a car crash many years ago, but we all actually face and try to hold off mortality (our own and that of those we love) every moment of every day, only we don't notice it because if we thought too much about it we'd drive ourselves and one another mad. We might not literally catch our death if we go out in this January's cold weather without the requisite hat, scarf, gloves, or thermals, but there is a kind of peculiar cumulative effect of every insignificant day and all its decisions on our health and how we prevent its premature conclusion. The creeping, daily insignificance of pain, or stress, or occasional distress: they seem just part of things, but they can add up to a diagnosis that backs us into a corner just like that grizzly bear.

Moments that changed my life? Being born. Growing up. Education. Getting married. More education: learning, teaching, more learning. Illnesses, whether of loved ones or my own. Wonderful friendships; reading wonderful books. Music. The theatre. Writing. Still being here.

But whether it's for myself or for people I love, what changes my life more than anything just now is the gift of another day. And another. And another. Even if 'a sad tale's best for winter', we're not all ready for that ursine pursuit just yet.

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