I read a book years ago in which one character described another succinctly in one or maybe two words. Sadly, the book was lost in a flood and I cannot recall the vocabulary used. Nor can I recall The author of the book.
The characteristic being described is what I have labeled as a "serial monomaniac".*¹ This person had one area of interest, which he focused on to the exclusion of other interests. But when he was satisfied with his experience with that interest he moved into another area of interest and focused exclusively on that area.
The hyperfocus and intensity of the interest are beyond what we would usually call flighty, fickle, or a dilettante.
I am not looking for Renaissance Man/Woman. That might describe an extreme version of this person, such as someone who completes law school and then studies medicine, followed by a stint in politics or business.
I am also not looking for fanatic, enthusiast, aficianado, nor fanatic.
Can anyone suggest a word that describes this characteristic? https://www.dictionary.com, https://www.thesaurus.com, https://www.merriam-webster.com, https://dictionary.cambridge.org, https://psychologydictionary.org, https://allpsych.com do not recognize the two word term.
As best as I am remember the first character says something like:
"Remember the two years you spent learning ()? And then you spent three years learning (). You focus so much I whatever you are interested in. John,you are such a ( ). I'm just not ready for that much intensity...about me."
*The term serial monomania has been used to describe this characteristic but I am looking for a simpler one word label. (See https://www.newyorker.com/magazine/2008/05/12/many-colored-glass-peter-schjeldahl)