"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.