Every company has an Allen who likes to talk about the most boring and inane nonsense.
In one company, we used to tell him to shut up several times in each meeting as we all wanted to get on with work.
Another company, I tried backing away from him. He followed. I was almost through a set of swing doors and the only thought keeping me sane was by moving a fraction backwards, the door would swing and hit his face. And I was so tempted.
Where I am now, the 'Allen' has the added disadvantage of having a flat monotonous tone to his voice. I have referred to him as a Dementor (from Harry Potter) as every time I talk to him I feel I have lost another bit of my soul.