Bad / Strange
absurd - (of an idea or suggestion) wildly unreasonable, illogical, or inappropriate

When Edwin Hubble in 1929 suggested that some of the little dots of light in the sky were other galaxies, many people though the idea was absurd, but he was proven to be correct.
fairytale - A children's story about magical and imaginary beings and lands; or something that is too good to be true or seems unreal.

He told a fairytale about how he got the job, but no one believed him, and people suspected that he had a relative in management.