Someone needed to send some bitcoins to another person they had a deal with and so asked for their address. The fellow sent an address and he sent the coins. Almost immediately, they sent a chat and was like "Have you sent it?" He responded in the affirmative and they exclaimed "Oh no." Even though they didn't give me details of the problem, I think it could be a wrong address or an inaccessible one.
I remembered this incident because sometimes, I do not cross-check addresses when I send small funds. Have you lost some bitcoins because of carelessness?
What are you most conscious about before clicking the 'pay' button?
Once, when crypto exchanges weren't widespread, I bought Bitcoin through a special service. When I sent them a hundred-dollar transaction to my card, they were obviously supposed to send me the equivalent of a hundred dollars in Bitcoin to my wallet. But what arrived was a thousand dollars.
I desperately needed the money and started wondering if there was some trick to keeping this crypto. But before the transaction, I filled out a special form, so they could find me. And my conscience would eventually notice. Of course, the operator asked me to transfer the excess crypto, which I did. I've never made mistakes.