sarcasm kills?!

So I'm not sure exactly what I said or did that convicted me, but I suppose I have been sarcastic a few too many times lately.... So today, I stumbled upon Proverbs 26:18-19.

It says:
"Like a madman who casts firebrands, arrows, and death,
So is the man who deceives his neighbor and then says,
Was I not joking?"

In another version, The Message, it states:
"People who shrug off deliberate deceptions,
saying, "I didn't mean it, I was only joking,"
are worse than careless campers
who walk away from smoldering campfires."

Quite a few years ago, I worked under a wise man who taught my friends and I that "sarcasm kills" and that we needed to do our best to stop being sarcastic to each other. At first we thought he was nuts; how could we realistically stop being sarcastic?! It was our culture; young people don't really have conversations without being sarcastic, do they? Some of the things he said caused me to take him seriously, though. He challenged me to think critically about it- most of the time, we are sarcastic because something is lacking. Courage, confidence, honesty, guts? I have found in observing myself and why I say some of the sarcastic things I do, most of the time if I am overly sarcastic there is a deeper meaning. I think that it is also a bit of a character flaw if used excessively; it is hard to tell what people are REALLY trying to say.... Why aren't we just honest and say what we mean more often? (It's hard!)

I admit, sometimes sarcasm is just funny and there isn't much beyond that. I think there are definitely instances where it is appropriate. But I have come to realize my boss was right- and so I have tried my best to refrain for the most part.
So I am going to start over again now....