"One of the main themes of the book is the beauty that mathematics possesses, which Hardy compares to painting and poetry.[5] For Hardy, the most beautiful mathematics was that which had no practical applications in the outside world (pure mathematics) and, in particular, his own special field of number theory." -- https://en.m.wikipedia.org/wiki/A_Mathematician's_Apology

G. H. Hardy, A mathematician's apology. I think that would be a good example here, since the focus is on finding beauty and fulfilment, instead of simply visiting every niche.

"Nevertheless, the fact is that there is nothing as dreamy and poetic, nothing as radical, subversive, and psychedelic, as mathematics. It is every bit as mind blowing as cosmology or physics (mathematicians conceived of black holes long before astronomers actually found any), and allows more freedom of expression than poetry, art, or music (which depend heavily on properties of the physical universe). Mathematics is the purest of the arts, as well as the most misunderstood."

Paul Lockhart, a mathematicians lament. I think this serves as another example.

I am one such mathematician.