question:  Why is it ironic that the narrator calls Doc his dad in the beginning?
context: I admit it: I didn't know if I was coming or going—but I know that if I stuck to the old man, I was a comer ... even if he was a goner! "Sure," the man agreed severely, prying a little worriedly at Doc's arthritic fingers that were clamped on his collar. I came alongside and carefully started to lever the old man loose, one finger at a time. If a half dozen winos in Seattle hadn't helped me get them loose, Doc and I would have been wanted for the murder of a North American Mountie. Doc's thin frame, layered with lumpy fat, was beginning to muscle-dance against my side. "'Memory Jump,' you mean. All my great-grandfathers have it. I told the human no, thanks, and walked Doc toward the flophouse three doors down. Doc was liable to say something that might nova Sol, for all I knew. It had happened a few times right after I first found him, but now it was worse. I tried not to think about it and helped Doc through the fly-specked flophouse doors. I found I couldn't focus both my mind and my eyes through the electric flashes of agony, so I concentrated on Doc's voice and trusted my hands would follow their habit pattern and construct the symbols for his words. Somehow, inside me, I knew that these words were what I had been waiting for. They told everything I needed to know to become the most powerful man in the Solar Federation. When I got to thinking it was just a dream and that I was dragging this old man around North America for nothing, I remembered who he was. I remembered that he was somebody very important whose name and work I had once known, even if now I knew him only as Doc. I don't know why, but nobody will help you if they think you are blotto.
output:  Doc is actually his dad, he only thinks it's a lie
options:  Doc is actually his dad, he only thinks it's a lie  His own dad is just as violent, so it's a fair comparison  He only met the Doc a few days ago and they don't know each other well enough to be family  Doc and the narrator are not actually from the same planet, and can't be related