I don’t know about all of it, but a heavy watermelon is well watered and more likely to be sweet since it’s had the resources to put tons of energy into growing all season. The same principle works for finding good citrus, you want something that feels heavy for its size.
Pretty much the only true ones are the ones about large webbing or orange/yellow field spots, because they indicate a watermelon that’s left to ripen for longer, but between natural variability and improved farming techniques, there’s no certainty.
Funny part is when they roll the damn melons, maybe hoping to help them ripen more evenly(?), and you end up with no distinguishable spot and usually a shit melon. Luckily you don't see many of those.
I hate almost all watermelon and other fruits in the squash family. Similar to cilantro and soap, there is a lesser known bitter chemical that I'm a supertaster of. I can taste if a slice of cucumber is dipped in a gallon of water. Love pickles, however, as cooking destroys the chemical. Those fake-ass refrigerated cucumbers in vinegar sold as premium pickles can suck my balls, especially when a restaurant puts them on a sandwich.
Yellow meat moon and star watermelons don't have this chemical, btw.
Anyhow, grew up farming. The thump test is the superior test for melons. There's a note they ring at that means a properly ripe and sugary melon, can't explain it. My wife has me pick out melons for her and the kids. Everything else is mostly superstition or unreliable like field spots. I can consistently pick a good melon or warn if I can't find a good one.
I'm pretty sure I have the same thing. People look at me like I'm crazy when I tell them cucumber has a strong, awful taste. I've had so many people tell me "cucumber just tastes like crunchy water" but it's SO strong to me.
Yup. I can smell a cucumber being cut across the house. Finding out I can tell sushi places to leave out the cucumber has been amazing.
It's also in cantaloupe, honeydew, yellow squash, pumpkins to a greater or lesser degree, some acorn squash. Zucchini almost never has it and I love it lightly grilled. I've found it in homegrown zucchini before, but never in commercial.
I hate yellow squash even when well cooked but I think that has more to do with childhood, or maybe it has an additional something in it. I can strongly taste when other food has been cooked with squash. Can also smell that musty smell when it's being cut that is different from cucumber/watermelon.
I've learned the slap strat. I like that sometimes I even get looks.
Ripe melons (at least locally) form cracks in the core. When you slap them the cracks allow the melon to reverberate. It's like slapping a double glazed window pane. Otherwise it's like slapping a shoulder.
Square ones: Nice to look at, but unripe and not very tasty. Use it as decoration don't try to eat them, also on the expensive side ¥¥¥¥¥ not really worth it unless you're going to attract customers to your store.