Is 4 the new 16?????

When did my 4 year old turn 16? I don't know what happened, but he is a hot mess. All of a sudden about a week ago he started getting lippy, talking back, making comments that he should not even know what they mean. Mike and I are at our witts end .. especially me, the one here with him all day. Tonight in karate class (his 2nd class mind you) he had the kahonas to actually tell his instructor no. What?! I went straight over to his instructor and said, "next time he thinks he is big enough to tell you no, give him push ups". I know it sounds horrible, but if I ever even THOUGHT about telling Mr. Bass no during class, he would have hemmed me up! We thought 3 was bad, and it was for certain things, but 4 .. whoa! He certainly acts too big for his britches.