For authors, for anybody, dressing up can be a way of "faking it till you get used to it," trying on a new identity when you aren't quite ready to claim it yet.
In both my writing career and my day job career as a philosophy professor, from the start I was asked to do things I had no idea how to do. I realized right away that I needed to form the policy of saying YES to doing them, despite my ignorance, inexperience, and terror. As a professor, I needed to teach courses I had never taken, review books outside my area of expertise, give talks on subjects where my knowledge was shaky at best. As a writer, I needed to write books on new subjects and in new forms. I needed to agree to give writing workshops even though I consider myself terrible at teaching writing.
I had to dress myself up, shove myself out the (literal or metaphorical) door, and do it.
Decades ago, when I had published my very first book, I was asked to give a school presentation. I had never given a school presentation. I had no idea how to give a school presentation. I had never in my life seen any other author give a school presentation. Remember that this was in the days before the internet, before social media, before You Tube, before all these resources were available to help us know how to do scary things.
I said, "Sure."
It never occurred to me to ask how many kids I'd be speaking to, or how old they'd be, or if they'd read my book. As the book was a tween title for 10-14, I assumed they'd be kids of that age. Used to giving academic talks at that time, I wrote out a 20-page text and came prepared to read it verbatim.
I was ready!
When I got to the school, I found that my audience were kindergartners and pre-K, filing in to a cavernous gym. I stood facing these wiggling little creatures clutching my 20-page speech. And I stood there and read it, droning through every word. I didn't know what else to do. The results were about as disastrous as you could expect.
But I came away with invaluable knowledge of how NOT to do an author visit. And now my author visits are pretty darned good, and I love doing them.
So: I faked it first. And flubbed it first. And learned a lot in the process.
Tricking ourselves into facing a fear is the best treat we can give ourselves. It truly is.