Looking like a tired @flipstar. I was trying to learn martial arts in the past - JKD, Muay Thai but I was just scared to break my tiny bones lol. I wanted to learn because you know the way I travel, there are many bad guys on the road. I even wanted to learn krav maga. I just hope I find time to learn some basic self defense before I travel again.
So far, I only know how to kick someone in the balls or hug him then pierce his eyes through my fingers! ;)
I think that are all good choices for self defense and the kick in the balls is already a great weapon in your arsenal, as we men dont really like that :-).
But besideds the self defense aspect it brings a lot of benefits.
If you find time and a shool and art you like I can only recomned it to give it another shot. I know you found many friends through longboarding and this is also true for martial arts.