My favourite thing about EXIF is its role in Hollywood and the news, e.g. "The geolocation from the metadata of this image verifies that this happened at this place and at this time", and other such nonsense nonsense. Always makes me chuckle.

My least favourite thing is colour profiles and how those can confuse grown adults and bring them to tears.

Same applies to file creation, modification and access times. Completely worthless but still would be valid in a court if you have the right "expert".