Abraham Lincoln and Millard Fillmore had the same title. They were both presidents of the United States, but their tenure in office and their legacy could not be more different.
The juvenile sea squirt wanders through the sea searching for a suitable rock or hunk of coral to cling to and make its home for life. For this task, it has a rudimentary nervous system. When it finds its spot and takes root, it doesn't need its brain anymore so it eats it! (It's rather like getting tenure.)