Elliot Costello is a social entrepreneur who co-founded the YGAP in 2008. YGAP finds and supports impact entrepreneurs with bold solutions to poverty in the world’s toughest communities. Elliot grew up in St Kilda, Melbourne, and is the son of Tim Costello, the CEO of World Vision and one of Australia’s most recognised voices on social justice, leadership and ethics.

Dear Elliot,

Being 13 is a challenging time of your life. I write to you with the same numbers in my age, but reversed.

I see the frustration you hold. You are leaving St Kilda Primary, so far the home of your education, and you are heading to secondary school. Unlike your friends at St Kilda Primary, you are not going to the local high school or Catholic boys’ college. Mum and Dad have, to your dismay, selected Caulfield Grammar School for you.

You are the only one from your entire school heading to Caulfield Grammar. The shock and anxiety is real. Every morning you will be boarding from platform two at Balaclava train station while your friends prance around platform one. Make peace with it, though. This is the best decision your parents will make for you.

There is a saying: ‘The only constant in life is change.’ You won’t know it now, but take my word that it’s true; and the sooner you comprehend it, the better.

Year Seven will be full of surprises. You find friends quickly, but take stock of who you associate with. It won’t be long before some of your ‘friends’ are requested to leave CGS. Teachers are fond of you but their patience with you will grow thin at times. The small piece of comfort you hold in that first year is choosing your sporting focus: basketball, football and cross-country running. Sport will continue to play a huge role in your life, so be grateful for your opportunities.

I know you’re feeling embarrassed. From time to time, you may even feel oppositional. Why do you have the boring father: a Baptist minister? He’s a Christian do-gooder who calls the most marginalised people in the community ‘friends of the family’. And he even makes the news for doing so from time to time. While all of your friends’ parents are pursuing legal, business and medical careers, you sheepishly whisper your father’s occupation. This faith that your father holds will begin to resonate with you personally some years from now. Eventually, you will profess to holding it for yourself.

The embarrassment is heightened when your new group of friends stay over at your place for the first time. Peter, a member of the community with mental illness, knocks at the door of your home. You know him, as Mum and Dad often offer him a cup of tea or quiet chat. You explain to him that Mum and Dad are away. While this is normal for you, your friends are shocked. It’s the first time you realise how different your upbringing is to that of your new friends from Brighton, Hampton and Sandringham.

It will surprise you to know that the love both your parents provide to our society’s most vulnerable, poor and disadvantaged will be a source of inspiration not only to you, but also many of your friends. For some, it will help shape and mould the careers they elect to pursue.

I encourage you now to embrace the difference. Own it. Be proud of your parents and the courageous – albeit different – lives they have chosen to lead.

Before long, you’ll be faced with some major peer pressures: kissing girls, drinking alcohol, wagging school and even breaking the law. Some of these experiences are not ideal; but all of them will help shape you.

There is one thing I will warn you against, though: smoking marijuana. It’s hard for you to understand right now – it’s accepted, or even encouraged, among your friends. But this innocent green plant poses the single biggest threat to you and all that you hold dear.

As a person who loves life – his family, friends and sport – you will be harmed by marijuana more than you think. It will burn small holes in your brain. Your studies will suffer. Your friendships will alter. You will become paranoid. Voices will appear. The way you engage with girls at a formative age will change. And it won’t be until you form an addiction, which takes two years to shake, that you realise how affected you are by this ‘experiment’.

I urge you to say ‘no’. Like some other friends, have the courage to resist this path. You are already different from everyone else; this is merely another way to embrace it.

Growing up in St Kilda – a multicultural, lower socioeconomic suburb of Melbourne – you will see many things others won’t. You will waste hours hanging out with friends at an arcade parlour run by drug dealers. You will be exposed to street violence and vandalism. You will disrespect authority. All of which seem normal to you. All of which keep your mother awake at night. And rightly so! You will one day lose a close friend in a stolen car, which crashed after a high-speed chase with the police.

The journey ahead is paved for you, Elliot. While turbulence lies ahead over the next few years – both within school and out – you are loved by so many around you. Teachers grant you asylum. You begin to settle down by Year 10 and grow into a sporting leader, high academic achiever and a well-loved member of Caulfield Grammar, all the while binding your old primary school friends into your new social network.

Take heart in your restlessness. Be kinder to yourself. Become a leader earlier in your life by saying ‘no’. And learn to embrace change – or even welcome it.

Every decision you make enables ‘us’ to become the man I am today.

Enjoy your teenage years,

Elliot