http://www.ncbi.nlm.nih.gov/pubmed/690806

Bit of an old one like, but still pretty interesting.

According to the clever people that carried out the research in the linked study above; the actual ridiculous happiness felt immediately after winning the lottery, reduces the pleasure obtained from the simpler things we do day to day – like having a cuppa.

After several months, lottery winner became miserable bellends, basically spoiled little sh!t syndrome had taken effect:

As predicted, lottery winners were not happier than controls and took significantly less pleasure from a series of mundane events

Apparently the same ‘adaptation’ occurs when you buy a house, or a new boat, or whatever it may be.   After a few months, you’re happiness is back to baseline.

In the study, the accident victims were slightly less happy, but not by much.  I’ll admit I have not read the full study, and just robbed that information from here:
http://www.forbes.com/sites/susanadams/2012/11/28/why-winning-powerball-wont-make-you-happy/