Joanna Cannon graduated from Leicester Medical School and worked as a hospital doctor, before specialising in psychiatry. Her novels, The Trouble With Goats and Sheep and Three Things About Elsie, were both Sunday Times bestsellers and Richard and Judy picks. Her new novel, A Tidy Ending, was published in April 2022. She lives in the Peak District with her dog, Lewis.

Ignasi Agell, Consultant Psychiatrist

1. On many occasions I have struggled between the yes's and the no's, and not always remembered a lesson from the past; that renewing your dreams is renewing your sorrows. A battle between light and darkness. My young self, I would tell to be curious; to live in the light of the dreams, because in darkness we can't see our shadows; to be authentic to overcome those shadows; and don't be a prisoner of your own opinions.

2. I was born with a club foot, to parents that were both deaf. I was always surprised when others asked how it was for me to have a bad foot, or to live with deaf parents, as for me this was my normal, my baseline. Later in life, other things happened; better or worse, and I learnt never to be defined by them, even when they became significant elements of my chronological life. We all appear to look for certainties in life, when our secret lives are made of little things. My young self I would tell not to be afraid and to become a gatherer of little instants.

3. Finally, to be kind.

Sue Armstrong, Literary Agent, C+W Agency

1. Please don't allow shyness to get in the way. You miss out on some incredible opportunities to meet iconic people and do once-in-a-life-time things all because you felt too shy to step forward. Put that feeling in a box and go forth and conquer!

2. That friend you adore? Keep him close. It may be an impossible situation but try to find a way, because 20 years later you'll still miss him.

3. Tips for uni: Jacob's Cream Crackers are not diet biscuits; DO NOT let that woman cut you a fringe; and remember night-time is for sleeping, daytime is for working, not the other way around (#Insomnia).

Hannah Beckerman, Author And Journalist

1. You're not the only one who feels the way you do

Everyone around you seems so happy, content, confident. They seem comfortable in their own skin in a way you don't. You imagine that you're the only person in the world who feels unhappy, depressed, unsure of herself. Trust me: you are not. Some people are just better at hiding their insecurities than you are. And you're so adept at hiding yours that many people look at you and have no idea how you're really feeling. But in time, you are going to find people to trust with these feelings. And even though they may never disappear altogether, you'll find that their power over you loses its hold once you dare to acknowledge them, articulate them, and share them.

2. Ditch the friends who make you feel rubbish

There's always one (or two, or three). Those friends who make you feel like you're not worthwhile. The ones who make you feel ugly, stupid, unlovable, unloved. They make comments that are supposed to be funny but are actually belittling. When you tell them something good that's happened to you, they've always done something better. In groups, they talk over you, steal your punchlines, make you feel invisible.

Ditch these people from your life. They're not friends. Your only purpose in their lives is to help smother their own insecurities. Your time - your value - is too great for that.

Seek out people who are genuinely happy for your successes. Who listen when you need to talk. Who care about who you are and how you feel.

And when you find those people, hold on to them, treasure them. Because they will be your friends for life.

PS: This goes for partners too. And family. Just because someone's related to you by blood or marriage, doesn't mean you have to tolerate nonsense from them. You don't have to tolerate it from anyone.

3. The race is long and, in the end, it's only with yourself (Mary Schmidt)

You look around you and everyone seems to be doing better than you. They're getting better exam results (apparently with no revision whatsoever). They are prettier, thinner, more popular, more successful. They're luckier than you: opportunities seem to fall into their lap. In time they will have jobs, homes, holidays that seem so much more impressive than yours. In comparison you feel less successful and, consequently, less happy.

Comparing yourself to other people will never make you happy.

Run your own race.

Don't just look above you, at people achieving more than you. Look around you; at your peers, at those who are aspiring to do things you're doing, and perhaps you'll see that you're not doing too badly after all.

The race is long and, in the end, it's only with yourself. In years to come, you are going to have this pinned above the desk where you write every day: both as a reminder that you are doing the thing you love and therefore it's immaterial what anyone else is doing; and as an acknowledgement that the only person who needs to be happy with the race you're running is you.

Ann Bissell, Publicity Director, Commissioning, The Borough Press

1. Dear Bissell aged 17

Your mom tells you to play the game but you don't understand why you should. So you are angry and disruptive and asked to leave school. You will still get your grades but why make life so difficult for yourself? Later, little one, you will discover that playing the game means challenging from within.

2. Dear Bissell aged 29

Oh you poor broken-hearted thing, putting all that love in the wrong place. You can't change people. This is a lesson you will have to learn over and over again.

3. Dear Bissell aged 35

A tough year for you. But you will dig deep and you will be very proud of yourself. Being with someone at the end of their life will change yours. You will learn that you are strong and kind and much loved, and that your family are the best people in the world.

Copyright: Joanna Cannon