Having worked at Miami for 30+ years, I've had the opportunity to work with some very intelligent and ambitious students. Many have gone on to establish very impressive careers in business and politics, among others.
The most difficult part of the job was always about the 'red tape.' As a higher educational institution, there are many political agendas that dictate what the University can and can not do.
The most enjoyable part was the students. Watching them come in as first year students, who were nervous and not very confident and then see them graduate as confident young men and women, who want to change the world in some way, be it big or small - that was very rewarding.
Too many irons in the fire at the same time.