Focusing only on fretless bass, that would be my point.
Even if I started on guitar when I was 16 years old (a crappy ekectric with a crappy amp paid the equivalent of 150 Euros with the little money I saved over the years), I've always been in love with that boomy lovely melodic sound I heard on records and mentioned as Fretless bass, which to me was a brand name back then. After my studies, so at the age of 22 years old, I bought my first real fretted bass with my first salary, then a few months later I had an Aria Diamond (Violin shape) defretted by Christophe LEDUC and started my journey in the fretless world messing with other instruments too.
Now, I'm 54 and discovered the ERB 8 strings fretless bass that I really love as fretless is my thing.
So, except focusing on the fretless bass only, just maybe having an official paper for my knowledge of the theory of music (but I can still do it).