What is the most useless job you had?

 In 2004 after completing my Master's degree in Telecommunication, I got a job as a support engineer in one of the govt university in Lahore. My JD was to go on tech calls from different depts mostly to fix antivirus or installing windows and level 1 work, at that time, I always thought I am wasting my time and energies there. But in fact, that job enables me to learn the basics of networking & IT support that in the long run, helps me to understand things from a different perspective. So no job is useless as you are learning something you might not know that will help you in future.