Why I do what I do

I question this sometimes. What are my motives behind certain things that I do? Why do I laugh and certain things? Sometimes I cant pin point it to anything specific. Most of the time I do certain things depending on my mood or who I am with. With certain people I may be more susceptible to laughing because I feel happy in their presence or I enjoy laughing around them. Maybe its a silly facial expression or something I admire about them. Maybe it just happens that they reminded me of something funny. I enjoy laughing. I am a serious person sometimes when the conversation or the people around me are discussing serious things.  There is a time and a place for all things. I am a firm believer of this and understand that its not appropriate to act in a certain way in the wrong situation. If someone is discussing something serious its not appropriate to laugh. It important to check your manors in certain situations to make sure that you act appropriately. Sometimes I don't understand why I do certain things. Its just a part of who I am.