I have had similar experiences with my sons. Of course, we all know about Mark Twain's observation on the relative learning abilities of parents and children. I have 3 sons, now 36, 32 and 28. About the time the youngest got to about 20, I suddenly realized that they had all metamorphosed from sullen, rebellious, and generally enraging little wretches whom I wanted, at various times, to kill, or at least sell into slavery, into normal human beings with whom it was actualy possible to have an adult conversation. Within a year or two, we all actually became friends. Now I'm thinking that some day I may have to apologize for some of the ways I disciplined them, but maybe not; those methods seem to have worked, although if I used them today I would be locked up.