Consider this Doctor. I have the means to take over this TARDIS, any time I want to. The beauty of solitude is that you can get a lot of work done. And believe me, I have been busy. Very busy.
However, you are far too young, too inexperienced to help me, aren't you? You have doubts, and as slow as ever, you arrive to the right conclusions when it's all too late. But you'll eventually understand. When the fabric of the universe rips, and all of time and space shudders in fear, you won't be able to run from me.