Even the most gutsy, confident and optimistic among us suffer from crippling self-doubt at times. It's inevitable to the human condition.
"Self belief is having good hair," so says immaculately turned out Cat Deeley. Similarly a great outfit can give you bags of self-esteem according to Giorgio Armani.
And if you ask George Clooney, the way to feel truly confident is to fake it.
From not comparing yourself to others to having life experience and embracing your self doubt and fear, if you're having a crisis of self doubt we are here to help. We've gathered the top tips, quotes and motivational advice from authors, actresses, singers and other high-profile celebs to help you climb back on to that high self-esteem horse.
We may see these personalities as being at the very top of their game, but many of them mention self-belief and confidence being a tough process involving a lot of self-doubt that they have to work at eradicating.
Enjoy their words of wisdom and hold those heads up high...
Former first lady
"We gain strength, and courage, and confidence by each experience in which we really stop to look fear in the face... we must do that which we think we cannot."
"Doubt can motivate you, so don't be afraid of it. Confidence and doubt are at two ends of the scale, and you need both. They balance each other out."
"Your self-worth is determined by you. You don’t have to depend on someone telling you who you are. I don’t like to gamble, but if there’s one thing I’m willing to bet on, it’s myself."
"Life is not quantifiable in terms of age, but I suppose in my fifties I am more grounded and more at ease in my own skin than when I was younger. I have a confidence that I didn't have before from the experiences I've had."
"I learned early on as an actor that confidence can be faked, and it's not always a terrible thing to do. A lot of times if people feel you're confident, then they're confident."
"I know what it's like to feel that fear and the need of affirmation and appreciation. To build confidence in yourself is the toughest thing."
"With any kind of artistic thing, it's a muscle, like any athlete, and the moment you're not doing it, you lose all confidence. That's why I'm terrible with down time."
"I understand how important hair is to a woman's self-esteem and confidence."
"I want to thank my parents for somehow raising me to have confidence that is disproportionate with my looks and abilities."
"To succeed in life, you need two things: ignorance and confidence."
"When I realised I had a facility for humour, I latched on to it, and it gave me confidence and I built my personality around it. So I subconsciously made myself become the funny one so that would be my label rather than the ginger one."
"Well, we all know that self-esteem comes from what you think of you, not what other people think of you."
"I feel so gratified about having finished college. I learned how to articulate myself. It gave me confidence more than anything."
Actress and singer
"I often find it's just the confidence that makes you sexy, not what your body looks like. It's how you feel about yourself that makes you sexy."
"I believe that my clothes can give people a better image of themselves - that it can increase their feelings of confidence and happiness."