I have too many calendars. I have a personal one and a family one, although I’ve yet to convince my wife to use that — she’s still using a paper diary despite the occasions where one or other of us stuff up and have to reschedule something. Sigh.
I also have multiple work calendars and unfortunately I can only get a holistic view of my life in Outlook thanks to oppressive policies from work.
I also have my history calendar.