I thought about that title before I wrote it. Surely there was a nicer way to say it.
But there isn't.
There has bee a lot written on the various common etiquette infractions that occur daily in Every gym. Here's a recent diatribe: http://www.mensfitness.co.uk/exercise/exercise_tips/7789/gym_crimes.html
In the end, it all comes down to one basic truth: the gym is a place to workout. It is not a coffee shop, a bar, or a school. In other words, if you are looking to chat it up with a perfect stranger, go to Starbucks. If you want to hook up, go to a bar. If you want to learn, or even worse, teach, go to school.
No one is interested in what you think, what you read in the new Muscle and Fitness, in how you workout, why or how you look. No one.
We are all here for the same reason: to increase our fitness levels. It does not require chat, jokes or spontaneous posing.
Take on open machine or bench, use it for the purpose intended, and then get up and move along so everyone else has an opportunity.
Don't be a dick.