This is a bit off topic but your comment reminded me of something I learned only comparatively recently: while these degrees are things we earn one at a time, they are sequential and the result is that your status (the degree to which you have climbed the academic ladder) does not accumulate, it only changes.

So at one point in time your mentor would have held the status / degree / title of Bachelor of Science. They were then promoted to Master, and then to Doctor.

That’s probably what you’re saying, and this isn’t really a correction. It’s simply something interesting that I wanted to share with everyone else.