Sara Barnard said this quote
“ Here are three separate but similar things: shyness, introversion and social anxiety. You can have one, two or all three of these things simultaneously. A lot of the time people thing they're all the same thing, but that's just not true. Extroverts can be shy, introverts can be bold, and a condition like anxiety can strike whatever kind of social animal you are. Lots of people are shy. Shy is normal. A bit of anxiety is normal. Throw the two together, add some brain-signal error - a NO ENTRY sign on the neural highway from my brain to my mouth perhaps, though no one really knows - and you have me. ”