Several years ago, I was introduced to “Matt,” who was about to begin working with a big, new client. “How do I deal with the feeling that I may have oversold them? What if I’m not really capable of delivering what I promised?” he wondered.

“My wife calls what I’m going through ‘imposter syndrome,’ ” explained Matt. “But whatever you call it, it is really making me feel like a fraud. I’m afraid that at some point, they’re going to figure it out.”

Imposter syndrome describes that collection of feelings of inadequacy that persist even in the face of information indicating the opposite. It is the feeling that you are not really competent but merely posing as someone who is. It often hits professionals at the worst possible time: when they’re negotiating an exceptionally large contract.

I told Matt it was OK to have this fear. “Instead of trying to fight it,” I recommended, “acknowledge that it’s there. It’s OK to be afraid, but take steps to do what you need to do to get rid of it. Become the expert you claim to be.”

The first step a person takes toward becoming an expert is declaring that he is an expert. Then, he needs to learn to walk the talk. “Get whatever training or materials you need to make what you told them into the truth,” I advised Matt.

I also advised Matt to trust his clients’ guts. “Believe that they have thoroughly considered your credentials and background. If they have more faith in you than you do,” I told him, “then you need to borrow theirs.”

Many of us have a gap between the reality of our abilities and what we perceive them to be. And in general, our abilities are greater than our perception of them (although sometimes it is the other way around). If the feedback you’re getting is overwhelmingly positive, trust your client’s or employer’s perception of you. They may be better at judging your abilities than you are.

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Sandy Schussel is a speaker, business trainer and coach who helps sales teams develop systems to win clients. He is the author of The High Diving Board and Become a Client Magnet. For more information, go to www.sandyschussel.com.