Every now and then, when my daughter Sophie is sad, I point into the mirror and say, “It looks like that little girl is sad. Maybe you should make friends with her and cheer her up.” I think a lot of us really need to make friends with the little girl or boy in the mirror. They are always going to be the one we see there. Are they as disappointed to see us as we are to see them? Do they wish someone else would look in at them? Maybe – but only because they wish that person would see them and smile.

You are going to be you for the rest of your life. You’re always going to look in that mirror and see yourself, no matter how disappointing you think that is. And the problem is that this disappointment will follow you into your day. It will reinforce your opinion of yourself, and you’ll find all the little reasons to doubt yourself or beat yourself up, and the next day that same sad person will look out at you, wanting some attention, maybe wishing you’d treat them in the nice way you treat your other friends.

If you saw another person looking at you the way your mirror self looks at you, you’d either think they were rude, or you’d think they really needed a friend. You’d probably want to help them. So why not treat yourself the same way? Most of us have had friends who sometimes needed a bit of a pep talk, and we’ve had to pick them up when they were feeling down. And these are people we might spend no more than an hour a week with. You have to live with you forever.

If you’ve ever had to share a room with someone, you know that annoying them or making them feel insecure has side-effects on your quality of life. Isn’t it important to make sure your permanent roommate is at least kept just happy enough not to cause you more trouble?

You will be you for the rest of your life. You really don’t want to be living with a crazed lunatic. But when you get down to it, people are fascinating. Instead of criticising yourself, why not come into the relationship with a curiosity about what makes you you? Observe yourself from the outside and try to understand how you work. Give yourself a pep talk when you need it, and remind yourself of what’s acceptable behaviour when you know you’ve overstepped the mark.

Your relationship will be up and down at times. Just don’t let that girl or boy in the mirror ever see you look disappointed to see them again.