Hmm, he said "extremely smaller". This does not sounds normal to me.
To Thatdude: did you have in the past mumps?
It is perfectly normal for one testicle to be larger (or smaller) than the other. Also, in many men, one testicle hangs lower than the other. Not to worry... this is normal. Your only concern would be if one had not descended and had not been attended to when young.