Appearances versus Reality

Has anyone ever considered you enthusiastic? Or overly enthusiastic?
Have you ever fooled yourself into thinking something based on past experience?
Have you ever met someone who has been fooled so many times that they get cynical, and are doubtful that you can really trust anything?

What happens when you misapply Kant's Categories?

Kant says:

The famous Locke, from neglect of this consideration [of the application of the categories], and because he encountered pure concepts of the understanding in experience, also derived them from this experience, and thus proceeded so inconsistently that he thereby dared to make attempts at cognitions that go far beyond the boundary of all experience. David Hume recognized that in order to be able to do the latter it is necessary that these concepts would have to have their origin a priori. But since he could not explain at all how ti is possible for the understanding to think of concepts that in themselves are not combined in the understanding as still necessarily combined in the objecf, and it never occurred to him that perhaps the understanding tiself, by means of these conceptsx, coudlb e originator of the experience in which its objects are encounterd, he thus, drivien ben necessity, derived them from expereince, I(namely from a subjective necessity arisen from frequentassociation in expereience, which is subsequently falsely held to be objective, i.e., custom) however, he subsequently proceeeded quite consistently in delcaring it to be impossible to gobeyond the boundary of experience with these ocncepts and the principles that they occasion. The empirical derivation, however, to which both of them resorted, cannot be reconciled with the reality of the sceintfic cognition a priori that we possess, that namely of pure mathematics and general natural science, and is therefore refuted by fact.
The first of these two famous men opened the gates wide to enthusiasm, since reason, once it has authority on its side, will not be kept within its limits by indeterminate recommendations of moderation; the second gave way entirely to skepticism, since he believed himself to have discovered in what is generally held to be reason a deception of our faculty of cognition. - We are now about to make an attempt to see whetehr we cannot successfully steer human reason between these two cliffs, assign its determinate boundeaies, and still keep open the entire field of its purposive activity.