Personality disorder?

In exactly one month to the day i will be 23 fucking years old! So it got me wondering when i'll actually grow up? I think that my main problem is that i make myself laugh too much. My sense of humour seems to spite me rather than enhance my personality - it most definitely does not make me a better person!). Today for instance one of my lecturers was discussing business model management - she stated that a particular type of analysis was originally called PEST which was then changed to PESTILE then to PESLIED and is now called STEEPLE. Now can someone please tell me why i was in actual tears of laughter after hearing this? bearing in mind that this was my first lecture and i didn’t know a single soul in the whole room. My situation wasn’t improved when she then played a video which had a rather fruity, milk bottle glasses wearing presenter from the 60's talking about engineering and its positive impacts upon society. I’m sure i’m still feeling the cramps in my belly. WHATS WRONG WITH ME??