That's part of the charm: No more macho way to go for a surfer. Drowning or getting smashed on rocks, means you are unskilled. If a shark eats you, then you become one with the sea.

That "failure to seroconvert" only means you did not develop IgG antibodies. You might have had some short term IgM antibodies. I would say no IgG means you need to be careful because you could catch it again, if you did have it. I'm pretty sure I'm in the same boat.