Why So RUDE?

ARGH!  I am so tired of everyone being so RUDE!  I mean, I am not always the nicest person, I DO have moments, as my husband and all my friends can attest to.  Most of the times my rudeness is unintentional.  It's done mostly when I am in a hurry or very busy and I instantly regret my rudeness and if I get a chance I do apologize for being short or unpleasant.

But in the past 2 weeks I encountered people who were just outright rude to me and I am just baffled. They were rude for no reason.  I was not doing anything to them. I was minding my own business, doing my own thing, when they just busted into my business.  I don't want use specifics, so I will use an example.  It was like you were at the gym, and you were using a piece of the equipment and someone came over - WHILE you were using the equipment and just started to change the weights while you were resting between sets.
This is how the conversation would go:

"Um EXCUSE ME?  I am still using this machine.", I say
 " But you were resting", says the rude person.
 " But I have one more set" I counter.
 " Too bad" says rude person, "You can use that machine OVER THERE".

First I was too shocked to do anything. I couldn't believe someone would be THAT rude.  I mean, we are in the South.  The courteous thing to do would be to ask if I was finished, or if they could work in between sets.  I am a reasonable person and I would probably have been happy to accommodate them.  But, to just take over like that and try to kick me off?  The ONLY thing that kept me from making a HUGE scene was that I didn't want to make a HUGE scene and my mother taught me not to yell at my elders.  Although, I do admit I lost it the week before and DID yell at an elder.  My patience only stretches so far at times.  ( sorry Mom ).