No – that is not wishful thinking; at least, it is unlikely to be for too long, because reports suggest WhatsApp might soon allow you to recall a sent message!
Believed to be called “Delete for Everyone”, the new feature will allow you to wipe out messages sent by mistake, before the person you sent them to has had a chance to read them. This has to be done within no more than five minutes, though. And not just this, the recalled messages will also not be visible on the Notifications Centre of your mobile phone – Android and iOS.
No final date for the rollout is known, so continue to be careful about what you send out till WhatsApp remotely enables the new feature!