I don’t think I can. I’m a fairly picky eater, and was extreme as a kid, but while I’ve gotten over a lot of my dislikes, at least to the extent that I don’t go “yeah, I’m not eating that”, cucumbers are still on my hate list. I don’t like the taste when it comes straight from a crunchy piece of cucumber, I don’t like it when it’s lingering in a salad after I’ve picked out all the bits, but I can cope with it, and I don’t like it in tzatziki, which is sad cause I sort of want to like tzatziki.
I don’t recognize your description of them at all, so it’s not that. In fact I can sort of see why people consider it a “fresh” and “clean” taste, but to me it’s just “blech, cucumber”.
I do also associate it slightly with watermelon, which I don’t much care for either, but I couldn’t say exactly what it is they have in common, other than being disturbingly close to water.
Some salt helps. Unless pickled, they just add moisture to a dish - not much flavour. I’ve seen the “old joke” above attributed to Sydney Smith and Samuel Johnson.
My father used to tell a similar joke about foods he wasn’t keen on. Basically: soak it in vinegar for 12 hours and then throw it in the dustbin (trashcan in USA-speak). Actually with cucumbers though, a vinegar treatment might improve them… I quite like an occasional pickle…
Actually, I agree with you about everything except lettuce salad, as I already mentioned. Potato salad should be mellow. The dominant taste should be potato, with maybe a hint of egg, and the tang of mayo and other mild herbs or spices. Putting anything like cucumber into it (or much worse, chopped pickle) is heresy!
First you disparage cucumbers, and now red onions! From your other posts in CS you seem to have excellent culinary tastes and standards, so I’m at a loss to account for these particular gastronomical failings. Here are the correct facts, according to me. White onions are mostly useful for cooking, and need to be sauteed in olive oil, but they are mandatory in raw form on hamburgers and (optionally) hot dogs. Red onions are to be served raw as basically a garnish that is excellent in many sandwiches such as smoked turkey (or sliced grilled chicken breast) with lettuce, tomato, and mayo, and are a nice touch when scattered over certain foods, like a plate of burritos, salsa, and sour cream.
Incidentally, I’ve never found cucumbers to have the kind of taste that I would ever describe as “bitter”, and I don’t peel them. Their contribution to salads is a combination of crunchy texture and what I would describe as a delicate fresh flavor, the flavor hinted at by the delicate garden-fresh aroma when they’re freshly sliced.
Maybe I’m weird, but I like the taste of radishes (raw, perhaps doused in lemon juice and sprinkled with pepper and salt; they have a nice sharpness to them), don’t mind the taste of cucumbers (fairly neutral tasting but with a nice crunch) but don’t think I can distinguish red onion from white onion.
I’ve never liked them except as pickles, or I can tolerate them mixed with something strong tasting like tzatziki or the peanut/ginger/soy mix of cold sesame noodles.
The unpleasant taste to me is a bit like soap rather than stale or leathery. I do get a similar soap taste from watermelon. A slightly bitter chemical inedible flavor.
When cucumber soaps and wet wipes became popular, my first reaction was “Well, cucumber tastes like soap anyway!”
I’m not kidding when I say it tastes like the scent of musty old books to me - I feel like you already described your dislike to the best of your capacity, whereas naita just said ‘foul’, which did sound like it might have a chance of unpacking to the same perception as mine.
Cucumbers have a very strong, bitter taste to me. It doesn’t remind me of leather or old books, though. I guess the closest smell for me would be grass, except much stronger and more bitter.
Several years back I got a food dehydrator and went on a binge of dehydrating just about everything that came out of the garden. For the most part it was a success. Then I tried dehydrating cucumbers. Smelled awful, tasted even worse. It was like smelling and eating dried grass. Just don’t do it.
I was wondering if the fact that some don’t like the taste of cucumbers was something like how cilantro tastes soapy to some people, meaning that it’s a matter of genetics. So I Googled. According to the pages I found, something called phenylthiocarbamide is the cause. It’s either tasteless or tastes bitter, depending on your genetics.
As one of the cucumber antis, I’ll add that my perception of them is utterly unlike leather or mustiness. Whatever their failings, they don’t have that taste to me at all.
Also FTR ref @Dewey_Finn’s good find about genetics, I enjoy cilantro and don’t have the cilantro = soap perception at all.
This whole thread is a fun unexpected disquisition through the variations in taste of a common food that really seems rather innocuous at first glance. Thanks for launching it. I hope we can shed some light onto your new-found perceptions.
A totally different thought just popped up.
This being the Year of the COVID, is it possible that your normal supply of cucumbers has been disrupted and you’re now getting a different cultivar grown in a different country with very different soils, fertilizers used, pesticide residues, etc.? Or maybe you’re now getting the extreme leftovers of last year’s (or two years’ ago!) crop normally sold as animal fodder.
Obviously this is not a factor if they’re coming from your own garden, but store-bought everything has had a lot more perturbations this year than most. And at least around here they’ve been in no hurry to tell us much about how extensively they’ve had to rejigger their supply chains to keep the shelves stocked.
Whatever has changed here, I seem to be the only one experiencing it - my wife says she cannot detect anything unusual about the cucumbers we’re buying, but for me, the flavour is sufficiently strong and unpleasant that I can’t eat them even in a mixed salad.
So there seem to be two options:
Cucumbers have changed in some way, and I alone, in all the world, can tell
Something has changed in me, but solely and specifically in relation to cucumbers
Obviously option 2 seems the more likely, but honestly, they both seem a bit weirdly specific.
From your other posts in CS you seem to have excellent culinary tastes and standards, so I’m at a loss to account for these particular gastronomical failings. Here are the correct facts, according to me. 
White onions are mostly useful for cooking, and need to be sauteed in olive oil, but they are mandatory in raw form on hamburgers and (optionally) hot dogs. Red onions are to be served raw as basically a garnish that is excellent in many sandwiches such as smoked turkey (or sliced grilled chicken breast) with lettuce, tomato, and mayo, and are a nice touch when scattered over certain foods, like a plate of burritos, salsa, and sour cream.