This morning I was explaining to a lady that I am very grateful to come to San Francisco because it is the epicenter for tech. She is an older lady working in traditional field unrelated to tech. So she seemed to be mystified by the tech activities mushroomed around here and asked me many questions.
This afternoon I was at a neighborhood coffee shop. I overheard a guy helping a woman running jupyter notebook sorting out the difference between test data and training data. It is an epicenter of tech for sure. Because You are just as likely to overheard people talking about what's going on in life as a discussion on specialized technical subject on the street.