If someone is "absent-minded", what does that mean?

It means that they are forgetful or unable to pay attention to things around them because they are thinking about something else..

It means that they are unconscious or asleep.

If someone is "well-off", what does that mean?

If food is described as being "mouth-watering", what does that mean?

If an idea, story or theory is "far-fetched", what does that mean?

It means that it's unlikely to be true and difficult to believe.

If a book or film is "thought-provoking", what does that mean?

It means that it makes you think a lot about the subject.

It means that most of the questions you had about the subject have been answered.