The first was the damage that institutions can have on human beings.
The second was that working within them was an enormous privilege.
Thirty-one years later, as senior service manager at Rainer Northamptonshire, Andrews has discovered something else: he doesn't like media attention.
Since being announced as winner of a Justice Award for his efforts in tackling youth crime, he has been pestered by journalists eager to know his secret formula. He tries to make clear he does not have one.
Andrews took on the warden job at the hostel run by the young people's charity Rainer on somewhat of a whim; testing out an itch he had to experience something more fulfilling.
He describes his first impression of the hostel as that of a "ghastly dungeon". "It was a horrific shock to go somewhere that was so institutionalised, with everything done in a regimented way," he recalls.
But by the following evening he found himself hooked on the work. He remembers sitting on the stairs of the hostel, with his colleague, a physically strong but gentle former monk, listening to the story of a drunken young man who had just broken a window.
"In all this oppressive regime, and amid all the chaos, there was a moment where we connected with him," recalls Andrews.
Andrews' role as warden was to keep young people in line. But when appointed hostel manager about 10 years later, the first thing he did was tear down all the signs from the walls, which he saw as symbolic of the "overtly controlling nature" of their environment.
He then embarked on a programme of "personal revolution", with reforms including the replacement of dormitory accommodation with single bedrooms and bedsits, to foster independence.
The high youth unemployment of the early 1980s ironically helped Andrews' mission, by sparking recognition of the need for better education and training. Young offenders became more involved in community and environmental work - something Andrews says helped change attitudes.
"It sort of liberated the young people and also the staff, as they no longer felt they were just residential workers," he says. "It also liberated the community, because we managed to get a dialogue going with the public."
In the early 1990s, the institution evolved into a bail supervision and support service, run by Rainer in partnership with the youth offending service, allowing young people to live at home with intensive supervision.
These days, Andrews heads an 11-strong team, which each year provides personalised programmes to nearly 500 young offenders on bail and remand.
He goes into courts and interviews young people, advocating for them if necessary and making a case for bail, often giving up his evenings and weekends to attend court hearings.
Andrews says efforts to changing young offenders' lives can be frustrated by successive governments' youth offending policies "going round in circles" and the public's "schizophrenic" attitudes towards young people.
But his team must be doing something right, having prevented reoffending for 96 per cent of persistent young offenders. So, what makes his team so effective?
Not giving up and building constructive relationships is the key, says Andrews. "I'm not being unduly modest," he says. "But if you strip everything else away, what you're left with is a group of human beings working together with a common cause."
FYI
- John Andrews, 54, was announced as winner of Outstanding Contribution to Tackling Youth Crime - one of five individual categories of the Government's Justice Awards
- He was presented with his award by criminal justice minister Baroness Scotland at a reception in London on 2 November
- Rainer works with more than 15,000 young people, including young offenders, care-leavers, homeless young people and those not in education or employment.
