"Don't worry, be happy," sang Bobby McFerrin more than 20 years ago, and entire industries geared towards promoting social and emotional well- being in all walks of life have been taking him at his word ever since.
But it is not just adults who are eager to find ways of approaching life in a more positive way; the art of happiness is increasingly finding its way into nations' classrooms as well.
For example, the Willy-Helpach vocational school, in Heidelberg, can justly claim to be at the vanguard of the "happiness lessons" movement in Germany. It all started three years ago after a nationwide survey revealed that pupils were of the opinion that "the only thing worse than school life was having to go to the dentist".
This galvanised the school's enterprising headteacher, Ernst Fritz- Schubert, into devising lessons, together with a team of experts, aimed at improving pupils' capacity for enjoying life, coping with problems and developing their personality.
Mr Fritz-Schubert concedes that "there are a lot of ways of doing this". In Britain, it was Wellington College that led the way when the school introduced a programme of well-being for its 14 to 16-year-old pupils some four years ago to help them cope better with problems of adolescence.
RE teachers received special training in "positive psychology" under the aegis of the Well-Being Institute of Cambridge University and classes were held once a fortnight.
At the Willy-Helpach school, by contrast, happiness lessons are an official subject on the state-wide curriculum that pupils can opt to study for the Abitur (German higher school-leaving certificate).
Mr Fritz-Schubert's methods, based on the principle of personal experience and hands-on projects, include role-play, exercises in concentration and self-awareness as well as sport and music, to boost pupils' self- confidence and encourage them to assume more responsibility for their own lives.
The idea is catching on. About 30 schools throughout Germany are trying "happiness" lessons, while several in neighbouring Austria are running pilot projects to introduce the concept as a school subject.
And how have pupils benefited? "The course made me more alert," said one girl, who added that she feels more alive and lives life more "intensively" as a result of the classes. Mr McFerrin would approve.