Rachel Weisz "doesn't know" how to blow-dry her hair.
The brunette beauty admits she makes a minimal effort with her locks, and insists she doesn't care if her tresses look less-than-perfect when she leaves the house.
She told InStyle magazine: "I'm a bit of a wash-and-go kind of girl. I don't know how to blow-dry my hair, so I never do. I have naturally big, frizzy hair, so I normally have at least two or three hairbands on my wrist.
"I don't mind not having the blow-dried look - I like a little frizz - and it's back in fashion, thanks God."
As well as admitting to being clueless about her hair, Rachel also struggles to maintain having nice finger or toenails, unless she can get expert help.
She added: "I'm not really a manicure person either. That's just not part of my life.
"If I have a red-carpet event, then it gets done and I can make it last a few weeks. And I love seeing nail varnish peeking through my shoes when I've had a pedicure, it looks lovely, but I just don't do it myself."