Danica Patrick has always given off a serious vibe on and off the racetrack. She has had her brash moments, which has earned her friends while alienating others.

Patrick has an explanation for the whole persona, and now 35, she can put perspective on the growth of her expressions.

"I've never felt like I had a chip on my shoulder about anything," Patrick says. "I would say that I have somewhat of a temper, so that would just kind of come out. I have no problem with conversation, confrontation, whatever you want to call it. So that makes my willingness probably broader than others. But definitely my anger and frustration, some of that was because I didn't want people to think that I was content with fourth or eighth or eleventh, or sixth or whatever it was, or second. I wanted them to know that I wanted to win. So somehow, I thought that being a little unhappy would get that message across to people, that I wasn't done yet. But I learned, fairly young, before I probably was 20 that I didn't need to put that face on every day. It was still difficult. I still have that face, trust me, but it wasn't something that I had to prove to anyone.

"I still get extremely disappointed with bad days, but I have learned that you can really perpetuate that by feeding it. Let's say you're miserable after the race goes bad or maybe even practice goes bad, you're miserable and then qualifying goes bad because you're still miserable. And then you're even more miserable, and then the race goes bad, and then all of a sudden you're miserable all week because you're not going to let yourself out of that jail cell of being like, 'I'm a victim of these things.' You've got to break free from that or else you won’t find yourself in a good position anymore. You might get lucky along the way here and there, have a good weekend. But you can’t make that your norm. So I believe that you have to be positive for positive things to happen, and so I found that out early on, especially as my NASCAR career when I came in because the races are literally one week after the next. If you let one weekend spill into the next, it becomes this pretty bad spiral, so I usually give myself the ability to be mad until I go to bed. And when I wake up the next morning, on Monday, it's over. Get on the 'happy train' again, and you've got to be positive."

"Danica," the documentary produced and directed by Hannah Storm, debuts on EPIX Wednesday at 8 p.m. ET.

-- Follow Jeff Eisenband on Twitter @JeffEisenband. Like Jeff Eisenband on Facebook.