For me it was my coffee/caffeine addiction. I know that my seems minor or trite but once I realized what kind of control this substance had over my body and behavior it helped me notice all the other influences in my life that impacted how I treated and behaved towards others.
I wasn't even that big of a drinker, I had maybe two cups of instant coffee while working home in the morning with a tsp of sugar each. Just a little pick me up to help me get my mind right for the day and help me wake up a bit. Pretty soon I noticed myself adding more coffee to the mix and more sugar. I went from making some when I need to be ON before an important conference call, to quickly not being able to functionally interact with others in anyway unless I had my caffeine fix.
And when I couldn't get my fix in time or satisfy my immediate impulsive desire for coffee, I realized I was acting like a child. I would be in a foul mood and blame others, I would sulk and not be any measure of productive. And then when I did get my coffee, I quickly became hyper aggressive towards others and felt I like I was the most powerful person in the city.
Eventually it was my wife who caught on to things and force me to quit drinking coffee because of how I failed to adequately manage my behavior with it.
Now after taking a break from it, I am able to notice it's negative affects on me, my brain, and those around me.
I often wonder what this means for others I've met while on the bean, and if I've ever really met who they really are.