Doctor Who Headcanon, Involving Face Caterpillars

(11 pic from here, 12 pic from here, edit by me.)

I have a theory. A headcanon. A possible occurrence of events that may or may not have happened. A thing I thought up, basically.

After having such a young doctor, the writers chose an older, more mature, less bowtie-y doctor for the next regeneration. Twelve has the things that 11 didn't. In that same respect, 11 had things that 12 doesn't (so far).

Eleven was always kissing people. Twelve isn't even a hugger.

I found it very hard to take 11 seriously, as he was always the guy in the fez. Twelve demands we take him seriously from the start by asking us to figure out if the robot guy jumped or was pushed.

Twelve is clearly a man, while 11 always remained a goofy, little boy.

Twelve has some wicked eyebrows. Eleven has none. *see pic above*

(Source)

Yeah. I know you probably started reading this with the expectation of a brill headcanon, with some unseen connection between 11 and 12. But no. It's about the eyebrows, and what they represent. Twelve is being all the things 11 wasn't. And that's nothing against 11: it's just not who he is. And I think in a way that happens with all the doctors. I can't speak for the classic series, but...

Nine was very serious: Ten could let go.
Ten had his demons: Eleven was happy 99.9 % of the time.
Eleven was terminally joyful: Twelve seems to be more serious. 

The eyebrows are more than face caterpillars. They represent something larger: the fundamental change from doctor to doctor. The give and take from regeneration to regeneration. How they can be the same person, and oh so diffrent.

Also, face caterpillars. I want to pet them.