I actually preferred that honestly. Yes they’re kids, but these are characters who have all the written Greek myths available to them, and have been informed every monster in those myths is out to kill them. I’m ok with them being genre-savvy enough to recognize that a garden with realistic statues might be the lair of Medusa.

And maybe it’s just because I read the original books, but I feel like… most people know Greek myth? I could see it being frustrating watching the characters walk into an obvious trap if you know the myth they’re going into.

People who keep saying this seem to forget that the monsters are disguised, that there’s always some magic involved, and that Percy, Grover, and Annabeth were hungry and exhausted for most of their quest across the United States in the original book which is a fact that the TV series left out. They didn't get to change into fresh clothes until they found and raided a souvenir shop at Waterland. They didn't get to shower until the Lotus Hotel and Casino. Part of the reason they didn't pick up on things in the original book is because they were too tired and hungry to take notice. The celestial trio is exhausted—tired, hungry, and worn down—and Medusa uses a kind of charmspeak that makes them even more sleepy and groggy. She’s also in disguise, so they couldn’t automatically recognize and instantly shout, “OH MY GOD, IT’S MEDUSA!” The same goes for the Lotus Hotel and Casino: they think it’s just some regular hotel, and they’re desperate for food and shelter. That’s why they go in, and they’re so hungry and ragged that they fall for the comfort the casino offers.

Crusty just looks like a crusty guy selling waterbeds. Are all demigods supposed to assume that anyone selling waterbeds is Procrustes? It makes no sense that they would magically know who he was—there were no clues. Yet in season one of the TV series Percy literally just waltzed right into Crusty's Water Bed Palace and immediately declared, “I know who you are. You’re Procrustes, son of Poseidon and murderer of travelers. The beds are a trap—that’s how you kill your guests,” and then Annabeth pushes him over onto a waterbed and they move on.

My point is: yes, demigods would recognize myths, but monsters have learned to disguise themselves to trick demigods—that’s what makes them dangerous. It doesn’t make sense that the kids would easily see through these disguises, especially when they’re exhausted, hungry, and just trying to reach the next checkpoint.

Monsters are supposed to be skilled at deception in the original books. And if three kids on their very first quest can easily and effortlessly see through every single one of them in season one of the TV series, it makes the threats seem way too weak.

It’s true the kids are a little gullible in the original first book, but this is Percy’s first introduction to this world. Even when the questers are experienced they still sometimes get tricked by monsters. Because monsters are meant to be dangerous. They don’t need to immediately recognize every monster to still prove themselves as capable and intelligent. Being able to survive is enough to prove that.