A different kind of Gwok Jing vs. Yeung Gor thread.
One thing that Gwok Jing and Yeung Gor shared in common was a goal to avenge their slain fathers. Their motivations, however, contrasted greatly.
Early in LEGEND OF THE CONDOR HEROES, Gwok Jing was determined to avenge the death of his father upon Deun Teen Dak. Later, when he discovered that Yeun Nan Hung Lit was the true culprit behind his father's death, Gwok Jing pursued YNHL with equal determination. Avenging his father was Gwok Jing's central goal for most of LOCH. This motivation, however, did not seem to come from within him...but from external sources (i.e. his mother; his Gong Nam 7 Freaks teachers). Gwok Jing never knew his father and, honestly, didn't suffer *that* much without him. Gwok Jing still had his mother and no shortage of excellent father figures while growing up (his archery teacher Jebeh, Genghis Khan and the Mongol generals, and the five surviving male members of the Gong Nam 7 Freaks). Gwok Jing understood that it was his duty to his father to avenge his death, but the motivation was always external. I don't know how much Gwok Jing could actually put his heart into avenging his father because he didn't personally suffer much from not having his father. Vengeance seemed more like an obligation and duty forced upon him by others rather than something he truly wanted to do of his own volition.
Yeung Gor was a different case. His desire for vengeance against those whom he perceived to be his father's killers actually had some plausability behind it...because he genuinely suffered from the absence of a father (although given who his father was and what he had done, it was probably for the best in the long run). Yeung Gor's mother Muk Lim Chi died and left him alone when he was still very young, and the absence of a father meant that Yeung Gor endured quite a bit of abuse during his childhood years. He had a few father figure possibilities (West Poison Au Yeung Fung, Gwok Jing, the Cheun Jen Sect Taoists), but these all went awry in various ways (some self-inflicted, others by fate). The point is, Yeung Gor directly suffered due to the loss of a father. Nobody ever obligated him to avenge Yeung Hong; that was purely his own desire and choice.