I know that 頭がおかしい means a strange peole, but would it be okay to say "私は頭がおかしいですが"? to meant "I'm a bit weird"?
My instinct said that it is quite unnatural...
Or is it one of the sentences below?
The sentence was meant to be used in a situation like this:
"I gotta warn you, I'm a bit strange (different in a good/fun way)!"