(as) silly as a wheel Australia simile
If you say that someone or something is as silly as a wheel, you mean that they are very stupid or silly.
He was as silly as a wheel when he believed in the woman who took advantage of his gullibility to scam him twice.
Her idea of using water to extinguish a blazing flame that derived from the gas leak is as silly as a wheel.
Extremely stupid
A very offensive term used to describe an upper-class British man who is stupid or inexperienced
Stupid or crazy
To be extremely stupid; not to be alert
The origin of this idiom is not clear.
1. Doing something extremely well
2. Behaving in an extreme or remarkable manner
1. Holly was in rare form during her speech, so she got the first prize in the competition last night.
2. Corrine: I'm going to buy Christmas presents for everybody. Do you want to go with me?
Laura: Oh...My kids are in rare form today, so I cannot go with you. Sorry!