The executive director of Aish UK is running on just three hours sleep.
Rabbi Naftali Schiff had left his office at 4.30am - hours before we met - to prepare for the Jewish education charity's first major fundraiser in a decade.
Chief Rabbi Ephraim Mirvis will be guest speaker at Wednesday's event, which Rabbi Schiff takes as a sign that "we've proven our colours. People know and trust us".
Sitting in his office at the organisation's headquarters in Hendon, north-west London, the 49-year-old shares his story through the myriad of photographs that surround him.
There's a picture of his grandson on the computer mouse-mat. There are images of Holocaust survivors with visible numbers on their arms.
We were naughty boys at school - a bit of creativity
He is seen standing beside leaders, including Israeli President Shimon Peres and Prime Minister Benjamin Netanyahu.
Together, the images tell his "Jewish journey" and now he's hoping to help young Jews fulfil theirs through Aish UK.
For the past 15 years, he battled communal mistrust of the organisation and has worked on a strategy to revitalise Jewish education in the UK.
He says: "There's a lot of misunderstanding about Aish.
"Our aim is to help people make an informed choice about their Jewish journey. When we started, we tried to reach out to the establishment of Anglo-Jewry but people weren't interested. They were nervous about a new kid on the block.
"So we said, we'll get on with the job. We'll raise the money, create the programmes, and go at it alone."
Since joining the organisation in 1999, Rabbi Schiff has raised at least £35 million for Aish UK and its sister charities. He has facilitated its access to university campuses as well as Jewish and non-Jewish schools across the UK.
As a result, it reaches "thousands" of 16 to 30-year-olds through a "serious fun" approach to learning.
Rabbi Schiff says that Aish UK educators were "naughty boys in school. They have a bit of creativity. They are young, normal, non-judgmental, compelling personalities.
"The establishment, they're all good boys. Same old, same old.
"I was a naughty boy in school. I caused a lot of trouble at the Hasmonean Israel society because in those days it was quite anti-Israel and I was an ideological Bnei Akiva kid."
But behind the jokes, Rabbi Schiff has a serious message to share.
The oleh, who returned to the UK to head a Jerusalem Fellowships programme, believes there is a "closing window of opportunity" to prevent more young people marrying out.
He says: "Marrying out is unfortunately the default position of the majority of young Jewish people today.
"There is no greater challenge facing us than losing our kids. Everyone knows this.
"Intermarriage is a measure of disengagement.
"Pride in being Jewish, connection with Israel, equals marrying in."
But he's confident that the numbers of Jews marrying out have fallen due to Aish's programmes: "A key benchmark of our success are the statistics of assimilation and success and intermarriage.
"In 2013, 20 per cent of engagement announcements in the JC were alumni of Aish programmes.
"Our aim is certainly not that everyone should become Orthodox. A success for us is a Jew marrying a Jew; a Jew committed to the Jewish people; a supporter of Israel; giving charity to Jewish causes.
"We want to smash down intermarriage and assimilation.
"Most parents and grandparents in Anglo-Jewry still want their kids to marry Jews. They're just not really sure how to ensure that."
Rabbi Schiff, who served in the Israel Defence Forces' Givati Brigade, says many communal leaders don't appreciate the generational change that has alienated many from the community.
He says educators need to adapt: "My generation was inspired to be Jewish by Israel and by the Holocaust. I grew up in a generation of post-Holocaust guilt, pride in the new state of Israel, the six-day war, Jerusalem.
"However, for my children's age group, it's irrelevant. Israel is just not the exciting adventure that it was for me and for my parent's generation.
"I think there needs to be a vision change in Anglo-Jewry. If we care about middle Jewish England we have to step up the bar and think strategically and on a larger scale."
He says Aish UK has made "mistakes" - one being that they "haven't involved parents enough". However, he claims that only a "tiny" per cent of people undergo a dramatic transformation after working with Aish UK.
Rabbi Schiff says: "In the same way that parents cannot prescribe the journey for their children, no organisation can prescribe a rate of growth and embracing of Judaism.
"Individuals who, quite frankly, come from unstable or troubled backgrounds, unhappy family situations where they are looking for something. It's very difficult to hold their hand.
"When you present a compelling buffet of Judaism for young people, they want to eat everything at the table all at once. Our intention is to unveil to opportunity to make informed choices about the Jewish journey."
Rabbi Schiff, who grew up in Kingsbury and read international relations at the London School of Economics, says he will remain in the position as long as he is needed - but does dream of returning "home" to Jerusalem.
He says: "From the age of 15, my intention was absolutely to live in Israel. If anybody would have said that number one, I would be living in England, and number two, outreach work - it was absolutely not on the cards."
Rabbi Schiff, who has rented the same house in Hendon since 1999, points to a picture of his home in Jerusalem.
"That's our house and that's the Kotel," he says. "It's the culmination of years of dreams. There was no other place to have children. My own children playing on the streets Jerusalem - it brings tears to my eyes when I think about it now."
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