In my TED video lessons, one of the videos I use with students is called 'Would winning the lottery make you happier?'. It claims that while it might make us happy in the short term, in the long run winning the lottery makes no difference to our overall levels of happiness.
This might sound surprising, but I think there's a lot of truth to it. Buying new clothes or a new car might make us happy temporarily, but the novelty soon wears off as we get used to them.
The video says that the things which bring us lasting happiness are experiences, not material possessions: for example, travelling to a new city or country, or learning a new skill (like a language!).
On a personal note, I definitely feel happier exploring Japan, meeting new people and trying new experiences than I did living my old life in London, even though I was making more money at that time.
So if you do win the lottery, think carefully about what you spend your money on!
What do you think? What is most important for happiness?