I am an introvert, but people at work usually don’t realize it for quite a while. I spent years “training” myself to be sociable and can do so quite effectively

I am an introvert, but people at work usually don’t realize it for quite a while. I spent years “training” myself to be sociable and can do so quite effectively, but I still dislike it and would much rather be alone. Sometimes that builds up to the point where I need to take time off work just to recover from social interaction.