If we envisage living to 100, we probably want to to get there like John Clement. He says he’s so busy he ‘can hardly get through the day’, he tracks his exercise routine with a Fitbit and carries an iPhone 6 (‘I always get the latest one’). And he carves wooden figurines, though he says ‘they’re not very good’.

He’s trying to think of a snappy, one-liner for people who ask him how he’s lived so longer. But he told his local newspaper the real reason: ‘I think life is all what you make of it. If you’re happy and enjoy life, why not live a little longer?”.

John hit 100 in Toledo, where he grew up. A pre-war Cornell engineering student, he was called up as a second lieutenant but spent his war in Michigan, overseeing factories turning out arms. After the war, he ran the family business Bock Laundry Machine Co with this twin brother, Carl. That hit legal difficulties, which John says wrecked the company and him. He retired in 1985 (briefly flirting with real estate but giving up after selling one house).

Plausibility rating: 8 out of 10. If we translate ‘being happy’ into longevity jargon as ‘a high level of subjective wellbeing’, then there seems a pretty strong correlation with longer life. The UK Officeof National Statistics says that it can add four to 10 years to life compared to low levels of ‘subjective wellbeing’. We’ll look at this in more detail in a future post.