I think it is very important to learn how to laugh at yourself and most importantly not taking life it self way too seriously. Life is so short, that you need to learn how to enjoy it, laughing frees endorphins which make you happy and make your body healthy. Personally, I am glad that I have learnt not to take everything so serious, not because I don't care but because I have to enjoy what I do in order to be happy. Now, I'm not saying that having a job is serious and as you should take life seriously you should quit or whatsoever, working doesn't have to be all serious and boring, you can spice things up, try being more creative even if you're 8 hours sitting in an office.
My recommendation is to laugh every time you can, and express your love to the ones you feel that are so close to you. You'll see how rewarding those small detail can be. I think that happiness is so overrated, they say you have to achieve whatever you whant in life in orden to be happy (yes you can be happy that way,too) but you can find happiness in the tiniest details like staring at your partner's eyes, like a nice walk in the park, helping others, you name it.