Phrases

Twice this week I've used phrases that others haven't heard of, both times I've been surprised!

Firstly I accused someone (jokingly) of being an 'Indian giver', and then had to explain its meaning - someone who gives a gift only to take it back again later or in order to receive something in return in the future.

The other one really surprised me that noone had heard the expression before, I said that I felt like a mushroom - kept in the dark and covered in shit.

I'm sure that's a well known expression?!