Imagine creating something so awesome that it would be perfectly understandable that you were a fan of your own work. That's exactly the type of life that George Lucas lives. If I wore a shirt with a graphic from my one-man show on it, everyone would think I was stupid. George Lucas could ride around Hollywood in a landspeeder and we'd all totally get it. By the way, are those things gas, electric, or hybrid?
No one can blame George Lucas for wearing a Han Solo shirt on the set of what we can assume is one of the Star Wars films (Kathleen Kennedy is seen chilling with him and Harrison Ford). The man created Han Solo, after all. If Harrison Ford wants to talk smack, George can just grab him by the lapels and say, "I made you. I can just as easily destroy you."