> ... I completely lose the ability to be a good worker bee ...

Caffeine in Floral Nectar Enhances a Pollinator's Memory of Reward - https://www.science.org/doi/10.1126/science.1228806

> Caffeine improves memory in humans, millions of whom find that their daily dose enhances clarity, focus, and alertness. The human relationship with caffeine is relatively recent, however, and thus its impact on our brains is likely a by-product of its true ecological role. Caffeine occurs naturally in the floral nectar of Coffea and Citrus plants. Wright et al. (p. 1202; see the Perspective by Chittka and Peng) found that caffeine presented at naturalistic levels significantly improved the ability of bees to remember and locate a learned floral scent and potentiated the responses of neurons involved in olfactory learning and memory.

PBS Eons Why Does Caffeine Exist? (5:13 for the bit on bees) - https://www.youtube.com/watch?v=PzshAqowsyI

> In experiments on bees, researchers have found that once they've had a sip of caffeine-laced nectar, it boosts their memory, makes them preferentially revisit the plants, and even helps them pollinate faster and more efficiently. So, for plants, caffeine is a multi-purpose molecule with a lot of adaptive benefits. But, for us, it has one main benefit: it gets us through Monday morning. ...

Chesterton called it, quite fittingly, "The Puritan's opium".

> Many (perhaps most) drugs cause harm at the wrong dosage.

Not only drugs, almost everything is bad at the wrong dosage. Case in point: water.

Depending on your definition of poison of course, but at least for LSD and magic mushrooms, all that's known is a lower bound for their biological toxicity. For LSD IIRC it's somewhere in the 30mg (!) range, for mushrooms it's more than can comfortably fit a stomach. I'm afraid I don't have sources handy though.

That said, the state of mind must be so wild that "is it poisonous in this specific/usual sense" is probably not the right thing to discuss.

So for mold, low enough doses aren't poison? Can't you just say this about anything. If you have poison in a low enough dose it's not poison. So it means jsut about nothing to say alcohol isn't poisonous because you can have a small dose of it.

Alcohol requires an astronomical intake compared to most drugs, and I'd say the indiscriminate action and lack of any particular affinity is what makes it a poison as opposed to a drug. It is also generally assumed that alcohol is not exactly in the same category as drugs. ("drugs or alcohol" etc.)