Enjoying early popularity in 1920's blues and jazz music, the guitar solo was thrown into music legend in the 60's buy guitarist such as Jimi Hendrix and Eric Clapton.
More applicably, someone can actually "be" a guitar solo if they make a statement or behave in a way that has become so desperately conventional or standard as to render the statement or behavior cheesy, sappy, and excessive (think motivational speakers).
"Heh, you city boys and your two-wheel drive trucks are no match for my Ford 4x4 and its killer towing capacity, heh."
"Dude, how many times did that speaker say 'in this economy' and mention how we needed to 'get er done' in order to get out of the recession?"
"I know dude, that guy was such a guitar solo. I seriously just wanted to start playing the air guitar right in front of him."
"It's not about staying up, heh, its about getting up after you fall down, heh."