...when the first thing you do when your animal is sick or injured is to take a picture of it for a future lecture, blog, or project.
This goes along with the other fact of vet school: Now that you are a vet, your animal will get all sorts of exotic diseases. Best to sell all your animals ASAP to a friend for $1.
And while we are on the subject of things only at vet school: overheard at an 8am microscope lab - "my microscope smells like sweat".
Ah yes, the joys of being in vet school.