Of all the minor injuries I endured when I was young, splinters were the things I dreaded the most. My father would sterilise a needle and gently pierce and peel back the top layer of my skin, then pluck the splinter out with tweezers. I haven't had a splinter for years, but the thought of getting one again has grown into an irrational fear.

So when my son got one in his finger the other day and asked me to remove it, I was far more terrified than him. To save him from anxiety, I did my best at appearing unbothered. I put his finger in my mouth, and pinched the skin between my clenched teeth and sucked. To my amazement, the fleck of wood slid out immediately. I felt like I'd just killed a bear.

Standing there, I realised that my sense of courage in recent times has come not from the big, obvious "brave" things. The removal of a 2mm piece of wood from my son's finger pumped me full of pride that day.

I wouldn't expect anyone to tell me I'm brave for doing that, or for riding a bike around town, as I have been doing a lot recently. I feel a newfound sense of daring as I cycle along main roads, speed down hills on the way to work, to the shops, or to pick up the children from school. This – if I am to look back in a few years' time – will be remembered as the summer of cycling. It doesn't sound very romantic, courageous or even that fun, but all the cliches, the wind whipping through my hair and cooling my bare limbs and the feeling that I'm travelling at 100mph, even though I'm barely going 20mph – are joys I've rediscovered.

For years I lost my nerve when it came to cycling. Even though I have always been perfectly capable, and once cycled to work every day, in more recent times I kept thinking that if I ventured out I'd be hit by a car or swept under a bus. I've never had a nasty accident, so where these thoughts came from, I have no idea.

"Be brave," I was told as a child when I'd fallen from a horse. "Get straight back in the saddle." And I did, because I was young and fearless.

As time went by, however, my love of boys overtook my love of horses. It's hard to remember if my courage for trying new things began to wane around that time too, but it feels that as my confidence slipped, so did my resolve. I used to look at other people doing the things that I wanted to do, and heap idolatrous praise on to them and their relatively small triumphs. "I wish I could do that. You're so brilliant!" I'd say, even if all they had done was applied for a job that was ambitious, or joined a band, or got a boyfriend who was clever, kind and handsome.

As my courage shrank, my life became pretty limited. And when I met R, I thought our courage blossomed because of the things we didn't do: save money, get a pension, discuss when to have children. We did everything that might have required some sort of planning in an unplanned and slapdash manner.

Someone once told me that alcoholics are usually an odd mix of huge ego and low self-esteem. I think I recognise this in R, but I most certainly recognise it in myself despite not being the alcoholic. Often in the past, when my fear about doing something grew, I pretended that I never really wanted to do it in the first place. Or I talked myself out of trying, by belittling it from the start. The things I said over and over that I didn't want in life were often the things I wanted more than anything else.

When R tells me how, for much of his life, he stopped himself from doing the things he really wanted to do because he didn't feel good enough, I can relate to that. Drinking gave him an erroneous sense of courage, the unhelpful kind that inevitably fizzled out when the night was over. It took him on limited adventures, in the same way that sleeping with lots of different men did for me: adventures that were easy and that didn't need much thinking about.

While they could sometimes be fun, the drink and the promiscuity ended up having a damaging effect on our sense of self-worth. We wanted to feel brilliant, but more often than not we felt wretched.