One day, both decided to cast their net from back of boat. Its translucent mesh spread out widely, dragging all in its wake. Yet while he began pulling in the net, a merman appeared to her. He told her this haul was a trifle compared to his sub-sea riches. Lulled by that seductive spell, the foolish fishwife absconded. A mighty tidal wave came and swept the fisherman far away. His boat became driftwood bits on a remote island's beachhead. However, he had held on to the net as well as its contents.
Hence did his solitary life commence set aside there. Although sweetest love was lost, he did become a better baiter. He caught everything from the slickest swordfish imaginable to Nereids who brought about reports of scarcity below. Alone he'd prepare the Fish Fry, starting with the biggest; supping on wonders of the deep but also fasting at times. During full moons, countless bioluminescent specimens came to pay him tribute and adorn his thousand-petaled coral crown.
The moral be: cherish whatever you yourself conceive. Unlike a fishwife deceived by the deeps!