Foreveryoung writes
To me, the speed of light should be infinite in a true vacuum.
It doesn't matter what you think it should be. Have you seen the effect on the speed of light that belief has? Try going outside and shout real loud "Hey, Light, you should have infinite speed in a true vacuum". I tried it, it made not a smidgeon of a difference.
After writing that, I can't get the sponge on a stick out of my head.