However, I believe strongly that you can only have a happy life if you love what you do in your day job too. 9-to-5 are too many hours to be miserable and wait for end of your work day[*]. Also you spend a lot of time with your colleagues. Life is short, don't waste that time.
I'm German, by the way, and I'm not sure how well my attitude fits the cliche;-)
[*] Don't you have a nicer word for the end of your work day in English? In German it is called "Feierabend", where "Feier" comes from fire but means celebration and "abend" is evening. So we have a party evening every day. What an apt word.*