When did you become a fan? Perhaps these two songs remind you of a certain time of your life that you have fond memories of? There are songs (BB and non-BB) that I know objectively aren't really all that great that I *LOVE* to hear because they remind me of a good time in my life.
I was raised in Hawthorne (till 13yrs old) so, The Beach Boys were something to feel proud of since I can remember, but I have to sadly admit it wasn't until the Summer Dreams TV movie that I really took an active interest in them. I went out and bough the Made In USA compilation, and hated everything on it past Pet Sounds! Of course that was more of a knee jerk than an honest reaction to the music. I was into "cool" bands at that time and couldn't be bothered with lumpen covers of Rock And Roll Music or Hungry Heart soundalike tunes.....
When Kokomo came out, I couldn't help but like the song and was happy that The Beach Boys had a number one hit again! It got me on my second big Beach Boys kick, so I dug out Made In USA again (remember, this was when Pet Sounds was still OOP) and, Kokomo being a big hit, Getcha Back stood out in a "why wasn't this as huge a hit" kind of way! I've loved the song ever since.