But you're wrong! That's exactly what the Aussie actress does in her spare time, if her recent interview with Jimmy Fallon is anything to go by.
Appearing on The Tonight Show, Robbie revealed she caught the tattooing bug after buying a tattoo gun on eBay.
She isn't painting koi fish down people's arms or anything. The 26-year-old Suicide Squad star specialises in doodles, usually located on feet.
Still, hasn't your Saturday been improved by this news?