There is a healthier approach than “Fake it ’til you make it.”

While it’s never a good idea to fake competence or knowledge, and pretending at a status or wealth level we don’t actually have is depressing (and in some cases expensive), there is some utility to practicing behaviors such as confidence. One visualization technique I’ve used before a presentation or a meeting is imagining how someone who is confident and a natural extrovert would handle the meeting. And then I just pretend I’m that person. Unlike a true extrovert, I require a bit of time to myself to recover afterwards, but trying on the personality of someone who might be more comfortable in the situation makes me more comfortable as well. And over time, I have honestly become more confident and comfortable in situations that used to inspire a queasy stomach and endless rounds of second-guessing. So don’t fake it until you make it, practice while you make progress.
