weird elevator encounter...

So I was at the ground floor waiting for the elevator.

It opens.

I see man leaning on the elevator wall, staring into space.

It's the ground floor but he does not go out.

I enter and press the 10th floor button.

He still does not press any button.

Elevator reaches 10th floor and I go out.

Man is still there.

WTF!

ANY THEORIES?

Here are mine...

• Some people walk around, smoke, drink, go shopping, go to the spa to relieve themselves from stress. THIS GUY RIDES ELEVATORS.
• He's just lost.
• He is brainstorming by himself and riding elevators is the best way to do it.
• I JUST SAW A DAMN GHOST.