At last, an answer to the age-old question, what is happiness?
Well, according to new research designed to measure pleasure, it is picking up a stray £10 note.
Scientists carried out tests on 80 volunteers whose brainwaves were recorded while they engaged in different activities.
From the readings, they produced a pleasure scale ranging from minus 100 to plus 100.
A surprise £10 windfall generated the highest average score of 82.9. At the other end of the scale, listening to badly played violin emerged as one of the most unpleasant experiences, with a rating of minus 55.7.
Playing with puppies scored 67.5, eating chocolate 65, and looking at pictures of smiling babies 50.9.
Off-putting images of rotten teeth or crying infants produced a score of minus 38.4.
Scientists at Birkbeck University in London measured activity in the prefrontal cortex region of the brain and correlated it with questionnaire answers.
The study was commissioned by chocolate brand Beyond Dark which - unsurprisingly - scored a high 65 on the pleasure scale.
It released the results on "Blue Monday" - the third Monday in January and traditionally the most depressing day of the year.
Broadcaster and consultant psychologist Dr Funke Baffour said: "We're all so busy rushing through life, it's easy to miss the moments of pleasure. Creating a scale like this reminds us there are certain things we can control every day to significantly boost our levels of pleasure, helping us combat depressing times like Blue Monday.
"Whether it's listening to beautiful music, giving someone a compliment or simply taking more time to show affection to your pets or loved ones."
Men were most affected by finding money, responding with a score of 90.1. Women scored 79.3, showing they were less impressed by cash windfalls.
Overall, women found life more pleasurable, recording an average 66.4 on the pleasure scale compared with just 58.2 for men.