My PhD student passed her viva yesterday. Of course she was relieved. So was I. Basically, a PhD is an apprenticeship in research. A student, who already has a first degree, spends typically three to four years doing research, then writing a thesis. The thesis is book length, often more than 200 pages.
Then the viva, where the student is examined on the thesis. And that is it. The student passes it and is done with being a student, usually forever. There is no higher educational qualification than a PhD, and so once you a PhD you have exhausted the education system.
So the viva really is the last exam. That is how my student described it to me. Very few fail, and none of my students have. Still after the viva the examiners sent my student out, then took some minutes before they came out and said she had passed. I got a bit nervous during those minutes. But it was OK.
We had pink champagne – proper champagne, not cava or anything. You only do one PhD viva, and even as a supervisor they do not happen every day.
Last exam? Working in software engineering, I have continued to learn new things throughout my working life, complete with occasional exams for certifications etc. I also opted to become a swimming official (both my sons swam for Hampshire) and had to pass exams for that too. We face tests of one kind or another throughout our lives. Remember passing your driving test and thinking that was it? I know what you meant, but for any student to believe they have finished learning/exams at that stage (and most do so after graduating) is a mistake.