You know...it really sucks when someone asks you for help, and you spend hours of your own time (with no benefit to yourself) talking about the problem with that person, and then the "help" becomes a heated debate because that person does not fully agree with or understand what you say, and then that person becomes exasperated and walks away without thanking you.
It's like the person has forgotten that he or she was the one who approached you in the first place. It's as if, by winning the debate or argument, you have somehow gained a benefit and no longer need the thanks. The person comes to you for help, then disagrees with your feedback, without recognising that the act of volunteering feedback - and of sacrificing all that time - in response to the request for help should itself be deserving of thanks.
Which really sucks.
