Came across this recently from my Chicago  friend, Lyle Dean.   No one has been able to accurately define just why  something is funny.  Up until now!  Funny man Alastair Clarke has broken  the code.  Throw away that seltzer bottle.  Grab a probability  calculator!  Here, for the first time ever, is THE SECRET OF COMEDY. 
A new theory suggests an equation for identifying the cause and level of our responses to any humorous stimuli: h = m x s.
The theory argues that human beings are more reliant for their  behavioural instruction on culturally inherited information than any  other species, and that the accuracy of that information is therefore of  unparalleled importance. Yet the individual is exposed to the continual  threats of error and deception, which can seriously affect their  chances of survival and success.
To compensate, humour rewards us for seeing through misinformation that  has come close to taking us in. The pleasure we get (h) is calculated by  multiplying the degree of misinformation perceived (m) by the extent to  which the individual is susceptible to taking it seriously (s).
Humour therefore exists to encourage us to take information apart and to  reject that which is unsound and could potentially harm our prospects.  Every time we laugh, we have successfully achieved this, resolving  inconsistencies in the fabric of our knowledge as we do so.
"I am not attempting to claim that we each engage in an algebraic  equation before we find something funny," says the author, Alastair  Clarke, "but that this schematic description reflects the instantaneous  reactions of the brain to potentially dangerous misinformation."
I'm sorry, that still doesn't explain Gallagher.  (This was a re-post)