"This is definitely the first curmudgeon, no doubt about it"

This quote by Stacy Keach is describing an individual who is irritated, irritable, and difficult to please. It indicates that this person is the first of their kind, and that there is no doubt about it. This could be translated as an amusing way of stating that this individual is the original grump, which they have actually set the requirement for grumpiness. It might also be analyzed as a method of revealing affection for the individual's ability to stay irritated in the face of adversity. It might also be interpreted as a method of revealing sympathy for the individual, as it implies that they have been bad-tempered for a long period of time and have not had the ability to find a way to be delighted. Whatever the interpretation, it is clear that Stacy Keach is referring to an individual who is hard to please and has actually been for a very long time.