I, too, used to think that Socks + Sandals = Doofus. Then last summer I sprained my ankle, again. I found that my sandals (with the adjustable velcro straps) were the only things that fit over the swelling, and being allergic to sunlight (yes, it happens), I needed the sun protection of socks.
As the late summer turned inevitably to early fall, I realized two things: (1) Socks + Sandals = Warm and comfy; (2) Life is too damned short to care if someone else is thinking "Doofus."
Besides, as someone maybe-famous once said, "You wouldn't care so much about what other people think of you, if you knew how seldom they actually do." ;-)