Can I say "this job is for a grown-up"? What is the difference?

What does "layout" mean?

"Layout" means the design in which parts of something are arranged; a kind of plan or organization of something. Ex: We got an architect to design the layout of our house. Ex: The layout of the newspaper is very disorganized.

What does "get in there" mean?

In this context, he is talking to the camera man when he says "get in there". So "get in there" here means he wants to get a closer view of his face in the camera, or he wants to see his face more zoomed in on camera.

What's "be convinced" mean?

To be "convinced" means to be certain of something and that you can't easily be persuaded to think differently. It can also mean to be persuaded to do something. Ex: I'm convinced that ghosts are real. Ex: Her friends convinced her to go on the ski trip with them. => persuaded Ex: Terry was convinced that Luna would say no to going out with him if he asked.

What does "what was I" mean and when can I use "what was I"?

This is not an example of a commonly used expression, but rather, a personal speaking pattern demonstrated by Bill Gates. Bill Gates means to say "what age was I," but he has omitted the word "age" from the sentence. It is sometimes common to omit words when they have already been mentioned previously. Because this is an example of a quick monologue or talking to oneself, the word "age" has been dropped.

What's "for life" mean?

"For life" means for the whole of one's life or for the rest of one's life. In other words, it means forever! Ex: Sam is my brother for life! Ex: They met in college and have remained friends for life.