The narrator succinctly informs us, the readers, about his nature in the final paragraph of this charming tale:
Funny. Different. Dreamy. Odd. How many times was I to hear that in the years to come, all spoken with the same quizzical, half-accusatory tone Sheila used then. Poor Sheila! Before the month was over, the spell she cast over me was gone, but the memory of that lost bass haunted me all summer and haunts me still. There would be other Sheila Mants in my life, other fish, and though I came close once or twice, it was these secret, hidden tuggings in the night that claimed me, and I never made the same mistake again.
The term 'funny' does not refer to the narrator's sense of humour, but suggests that he was somewhat eccentric. This is emphasized by the deliberately redundant references to him being 'different' and 'odd'. It implies that he was unconventional in the manner he did things and others could not always understand or appreciate his mannerisms. In the story, for example, he is more drawn in by the idea that he could capture the bass, than by Sheila Mant's conversation and her supposed charm.
His oddity is further emphasized by his decision to take her on a date in a canoe, when a car would obviously have been a more convenient choice. It is probably this 'oddity' which draws Sheila to him when she accedes to his request. As he calls it, this is his 'trump card'.
However, even though the narrator was obviously overwhelmingly infatuated with Sheila, his love for fishing dominated their entire trip, since all he could think of was capturing the large bass that he had inadvertently hooked. He generally ignored her. Two quotes confirm this:
... it was a few minutes before I was able to catch up with her train of thought. and
... Sheila began talking about something else, but all my attention was taken up now with the fish.
For someone who had so much longed to be with Sheila, it seems quite strange that he declares:
The rest of the night is much foggier.
... all I really remember is her coming over to me once the music was done to explain that she would be going home in Eric Caswell’s Corvette.
His thoughts were clearly dominated by his experience with the bass and the lost opportunity to capture it. We do learn, however, that the narrator had no regrets about the wasted evening with Sheila, but that he had certainly learnt his lesson regarding the bass (which he had let go by cutting the fishing-line). He asserts, finally:
... I never made the same mistake again.
However, the memory that haunts him most is the one of 'the lost bass'.
The fact that the narrator also refers to himself as 'dreamy' implies that he was always lost in thought - a dreamer, probably an idealist and someone who had a lot to think about. The fact that he loved nature and devoted so much time to fishing, further suggests that he was a romantic - someone who aspires to and believes in the greater good.