2+2+2=7
Teacher: If I gave you 2 cats and another 2 cats and another 2, how many will you have?
Johnny: Seven, Sir.
Teacher: No, listen carefully. If I gave you 2 cats, and another 2 cats and another 2, **how many will you have?
Johnny: Seven
Teacher: Let me put it to you differently. If I gave you 2 apples, and another 2 apples and another 2, how many will you have?
Johnny: Six.
Teacher: Good. Now if I gave you 2 cats, and another 2 cats and another 2, how many will you have?
Johnny: Seven!!!
A very angry Teacher: Where the fuck do you get seven from?!?!?
Very angry Johnny: Because I've already got a fuckin' cat at home!!!**