I forgot my false mustache

Laugh lurker (noun): one who lurks whilst observing others laugh and sets out with a purpose of discovering quantities and origins of such laughter.

In my head I had envisioned myself wearing a totally inconspicuous fishing hat, those funny glasses with the false nose and mustache attached, and camouflage pants. I was going to casually hide in the bushes as if no one could see a giant green and brown bottomed person doing an army crawl through the shrubbery. I planned to mentally record the when/where/why of laughter in conversations of innocent passerby on which I just happened to eavesdrop. The plan was nothing short of flawless.

 

Then came the realization that I owned neither a fishing hat nor camouflaged-patterned pants. And I had misplaced my false mustache.

So, I was forced to settle with Plan B, albeit its anticlimactic nature compared with Plan Mustache. Plan B was as follows: 
A) Participate in conversations.
B) Do nothing unusual.
C) Pretend to not be mentally taking note of every time someone laughs.

Success came at last! As I was pretending to be normal, I observed that in casual conversation, most laughter does not stem from truly "humorous" situations or contexts. Most of the laughter was rooted in pure friendliness. Without laughter, conversation seemed dull, uninteresting, and unfriendly. Laughter adds cheer and makes light of the darker sides of life, and it doesn't have to be a result of something considered humorous.

A lot of people laughed in response to feeling slightly awkward or uncomfortable, too. I know that I personally do this, especially when meeting someone for the first time. To me, this fits in with the Relief Theory of humor. Many of us let out nervous or pent-up energy through laughter, because subconsciously we know that laughter releases endorphins and makes us feel better. We aren't laughing due to experiencing something humorous, therefore. We laugh, essentially, to release emotions and keeps ourselves from exploding.

In daily conversation, most laughter represents friendliness and release of excess energy. We like to laugh, but we also like sharing our laughter, so we do it with others around and in response to things that are not necessarily hilarious. Someone wrote once that happiness is only real when shared, and I believe that is what humans do every day of their lives: find someone with which to share their happiness. This happiness is represented with laughter.