There's an interesting answer to "How long did it take Columbus to realize he wasn't in Asia?" at https://www.reddit.com/r/AskHistorians/comments/sfzx1/how_long_did_it_take_columbus_to_realize_he_wasnt/c4drgqf/ by /u/jabbercocky .

This is intended as a starting point, not to discourage discussion. Especially because that reply is about Columbus himself, but you asked about "Europeans", presumably Europeans in general. Further questions, links, info, and debate are welcome.