My cat has always said that he feels any drug, whatever its purpose (medical, recreational etc.) will with regular use will have a gradually lessening effect (whatever that effect might be), and that the subsequent dependence (meant in a very loose way) on any substance has the long term effect of working in the opposite direction.
Thus, as an example, he suggests that drinking coffee as a stimulant (which he does despite it not being recommended for pussycats) has a long term depressive effect (though obviously rather mild, even in felines).
On discussing this with a Scottish family member of a less-domesticated genus, it was suggested to him that his idea was pretty much the guiding principle of homeopathy - though the concentrations used in that art are apparently so tiny as to be chemically indistinguishable from water.
His thoughts have recently returned to this concept with special regard to nootropics. For instance: were it possible to find a substance which made it harder to remember things whilst under its influence, would long term usage actually work to improve retention?
I should mention that in our conversations, he talks English, as my Cattish is quite weak. So to try and clarify: I'm certain he doesn't mean a chemical which makes you forget things you already have memorised (such as the one-and-a-half bottles of cognac he had last year which made him forget even the basic instinctive functions of an animal), but a drug that inhibits memories forming at the time.
Do any of the readers' pets know of a substance which might fit this description? Furthermore has any of them ever experimented with this theory?
Note to moderators: he's a clever cat, but I'm sure this thought may have occurred to other animals before now. However he couldn't find any reference to it on the forum. He would not be embittered were you to direct him to another thread and to delete this one, should such a topic have already been discussed.