Greed

I found the definition of Greed, because English is not my mother language. It is a strong desire that for more food, money, power, possessions etc than you need.

Today, I found two beautiful glasses of Licher beer on the beer box. As soon as I saw these glasses, I felt like taking one of them. No hesitation and no consideration. After all, I asked one friend who is in charge of the beer box to take one of them. He said, "yes, no problem." Finally, I got the glass.

Actually,I don't need more glasses to drink beer. Anyway, one glass is OK, but when I feel more than one glass, how can I control it?

Where does this greed come from?