The `Bel Ami` actress - who has 13-year-old daughter Maya and 10-year-old son Levon, with ex-husband Ethan Hawke - turns to her profession to calm down because she often drives herself "nuts".
She said: "I`m not very relaxed naturally. I`m one of those highly focused, overly intense characters. I often drive myself nuts.
"I actually find work can be quite relaxing. When the children were little I wasn`t able to work like I did before.
"So now, when I do work, it`s very much like, `This is good, this is my time.` "
The 41-year-old star - who is believed to be pregnant with her third child, which will be her first with boyfriend Arpad Busson - admits she wouldn`t have believed anyone if they had foretold her how her acting career would pan out.
Uma - who has starred in hit movies `Pulp Fiction` and `Kill Bill` - added: "If you had sat me down and gone through some of the challenges I would face and what I would overcome and grow through, I probably wouldn`t have believed any of it."