Fingernails
You just have long nail beds. My nail beds are short, so after just a few days, I have a 'free edge' to my nail, even though my nails are still rather short.
I think my fingernails must be different than most people's.
When I cut them down-- the nail (thumb, second and third as mentioned above) is actually below the skin line (if you look at the finger from the lateral aspect) -- and, as I said, I still have white.
You just have long nail beds. My nail beds are short, so after just a few days, I have a 'free edge' to my nail, even though my nails are still rather short.