1. Bowties
Bowties. He wears a bowtie because bowties are cool, enough said. Like with the tweed jacket, the bowtie was Matts idea, and Steven said no, Matt put it on, and Steven said yes. To me, the bowtie also plays with the idea that Eleven is an old soul, an old doctor. Since the actor is so young, the costuming had to lean towards conventional older peoples style to remind that, despite the Doctors face, he's actually ancient. The best example of this is when he puts on the bowtie for the first time after the Ponds, and the audience can see the Eleven we know and love come back into his face. He loves the bowtie, he loves his wacky style, and the bowtie is the pinnacle of wacky style. The bowtie also ties into the Doctor attempting to be cool and, well, failing a bit (or a lot), such as how he is known for being a toddler in a mans body to the fandom. In A Good Man Goes to War, even baby Melody apparently tells the Doctor that she doesnt like his bowtie. Its geeky and wouldnt be cool on anyone else but Eleven. Matt successfully took something that was known for being nerdy or geeky and making every Whovian own a bowtie. Okay, my list is done, what will forever remind YOU of Eleven?