Margot Robbie is driven ''insane'' by her own thoughts.

The 'Suicide Squad' star hates to be alone with her thoughts and tries to do everything with her other half Tom Ackerley or her friends.

She said: ''I never do anything on my own. I don't see the purpose of doing anything if I don't do it with my friends. I go mental when I am on my own; my thoughts are so loud it drives me insane.''

And the 28-year-old actress was fiercely independent as a child.

She added to ES magazine: ''We weren't easy kids, we didn't make it easy for Mum. When I was five I was watching my mum put spread on my sandwich for school and I was saying, 'It's not going to the edges', and she was like, 'If I am not doing it right, do it yourself.' So I started making my own lunch from five years old. If I wanted something a certain way I just did it myself. Mum says it sums me up. I'm still trying to make it up to her.''

Meanwhile, Margot previously revealed she is an expert in saving money.

She said: ''I can be so f**king thrifty. Saving money is my area of expertise. It's a good skill to have for reallocating funds in a film budget. Any room [in that flat] that wasn't already a bedroom would become one. So we didn't have any living rooms, just bedrooms. It was all very close-quarters.

''I loved London so much; riding the Tube. Also because the paparazzi can't follow you. I miss walking down the road to go to the pub - we've talked a lot about opening an Aussie pub in LA. Being in the world and getting to watch people interact, it's helpful as an actor being able to do that rather than being locked in a car. It's hard to get perspective in LA.''

The full interview appears in this week's issue of ES Magazine, Thursday 19th July.