Came lookin for an answer and since there is none, I'll give my take on the meaning...
A moment of limbo. Author finds himself going crazy with uncertainty using the analogy of knowing whether he should become a landweller vs water creature to compare the journey of meeting people and keeping casual relations by being a fish in the sea telling himself there's plenty of them (like the saying) versus, allowing the relationship to evolve from being a fish to a dirt dwelling lizard according to the Darwinan theory... to explain the sure footing such as a firm relationship can offer when it takes root on firm grounds.
Past love heartaches seemingly impede him from moving forward when a promise is made by someone... and the uncertainty of not knowing whether he's found a special someone that he shouldn't pass up is troubling him along with the pure agony of going thru a bad heartbreak again in the case that it would not be meant to be...
Came lookin for an answer and since there is none, I'll give my take on the meaning...
A moment of limbo. Author finds himself going crazy with uncertainty using the analogy of knowing whether he should become a landweller vs water creature to compare the journey of meeting people and keeping casual relations by being a fish in the sea telling himself there's plenty of them (like the saying) versus, allowing the relationship to evolve from being a fish to a dirt dwelling lizard according to the Darwinan theory... to explain the sure footing such as a firm relationship can offer when it takes root on firm grounds.
Past love heartaches seemingly impede him from moving forward when a promise is made by someone... and the uncertainty of not knowing whether he's found a special someone that he shouldn't pass up is troubling him along with the pure agony of going thru a bad heartbreak again in the case that it would not be meant to be...
[Edit: Further clarification]