Sure

One of the lessons I have learned from being in the work I'm in is that one has to be sure of himself/herself during life. When one shows the least bit of hesitation or insecurity, the people around them tend to shy away from them and try to find someone else with a little more confidence. People don't trust someone that acts unsure and hesitant.

In my line of work, if you act unsure, the customer will give you a "look" and go on to the next available person that will help them with their problem. I learned long ago never to volunteer for anything where I didn't feel confident. Several times I ended up being forced to do something where I was not at all sure of myself and ended up making a fool of myself and creating animosity in the customer. From those experiences, I learned to act confident even when I knew I had no clue what I was doing.

My advice for people is to go out in the world full of confidence. Know you are you and convey that knowledge to the people around you. One doesn't have to lie about one's self to gain confidence. The lies will eventually find their way out of the facade of self-confidence that one wear and will shatter any trust that people had in the person. If you are not sure of an answer, still act sure but let them know that you can find out more about it for them. If you are unsure of a task, do it with confidence to the best of your ability. If something goes wrong with the outcome, you will have learned something in the process.