Very few people would characterize me as shy. Based on the classic "Big Five" personality factor model, I score heavily on the extroversion scale. Yet there are definitely times in my life when I have felt shy, or a reasonable facsimile thereof, and I've concluded that there is a pattern.
First, I'm more likely to feel shy in unfamiliar settings, when I'm surrounded with unfamiliar people.
Second, the level of shyness I feel is generally inversely proportional to the level of status I feel in that setting.
Here are a couple of examples, that help illustrate these principles at work.
Over a decade ago, back when I was still an unemployed bum during the dot com bust, I attended the Silicon Valley Forum Visionary Awards. Since I was a volunteer, I got to attend the invitation-only event, which took place at some successful entrepreneur's luxurious estate, and was packed with famous and wealthy. On the bus ride up to the estate, I sat next to one of the honorees for the evening, legendary founder and investor Andy Bechtolsheim, who was both incredibly smart and probably one of the nicest people I've ever met.
It was an unfamiliar setting, filled with unfamiliar people, and I was clearly one of the lowest-status people there, other than the catering staff. While I had a good time and chatted with a lot of people, I felt much shyer than I would have at a less high-faluting event. A symptom of this is that I spent much of the evening hanging out by the food with other low-status volunteers in attendance, like Jonathan Abrams, who told me about a startup he was about to launch called Friendster, and some developer relations guy from PayPal named Dave McClure.
Fast forward to last year's Visionary Awards, which I also attended. This time, I was there in my capacity as a member of the Silicon Valley Forum board, which meant that I was now a host of the event, imbued with positional authority and status. It was now my job to work the crowd and make sure people felt welcomed to the event. Quite a change from being an unemployed bum filling up on crab cakes!
It was the same event, full of famous and wealthy people, but thanks to the twin factors of familiarity and status, I now had a very different experience (though I had a good time both years).
(Incidentally, if you're interested in attending this year's Visionary Awards, reach out to me, and I'll try to get you an invitation. I promise, I'll introduce you to interesting folks!)
There are very few occasions on which I feel shy these days, but I would argue that this is due to environmental changes, not psychological ones. Most of my time is spent here in Silicon Valley, where, even if I don't know the folks I'm meeting with, I'm very familiar with the mores and customs of their tribe, and we likely have a host of mutual friends and contacts even if we don't know each other yet. In addition, even without Silicon Valley's primary marker of success (starting a billion-dollar company) I have enough secondary markers (best-selling author, teaching at Stanford) that my status is high enough to allow me to feel comfortable in most company, despite my embarrassing lack of private jets, vacation homes, etc. I'm sure I would feel very different at an Oscar party in Hollywood, where I would be in an unfamiliar millieu with essentially zero status (imagine being at a Silicon Valley party without any knowledge of the industry, and without even appearing in Crunchbase or Angel List).
So if you do have a tendency to feel shy, maybe the answer isn't to try to change your personality, but rather to change your situation. Develop a familiarity with the millieu; you might use your first year in attendance at an event to familiarize yourself with the customs and layout, and then return the next year with greater confidence. You can also use the technique that I did (intentionally or unintentionally) with the Visionary Awards, by acquiring official positional authority and status. Maybe you can volunteer for the organization that puts on the event, or if you're really gung-ho, organize your own! This will also help you with your status at the event, and maybe even boost your overall status.
As I'm fond of saying, if you know the world is rigged, why not rig it in your favor? You might be naturally shy, but if you rig the situations you find yourself participating in, you can arrange your environment so that you never feel shy.