Maybe it doesn’t count as being stood up if that person has actually cancelled that day and advised you of it. Some people might be angry or disappointed if they were to be cancelled on not once but twice. Not me! I love it when people cancel on me because that means I don’t have to socialize and can cocoon myself on the couch instead. That doesn’t mean I don’t enjoy the company of the person who has cancelled on me, it just speaks to how much I enjoy being alone.
Introverts unite! Individually.