Glasses and problems

But now it is not necessary. My question here is how: What happens if I keep it in a glass for a few minutes?
 - Nothing!
 - Really, nothing bad will happen - said the professor. - And what will happen if I tried to keep the glass at arm's length, for example, two hours?
 - Your hand starts to hurt.
 - And if the whole day?
 - Your hand is numb, you will have a strong muscular disorder and paralysis. Maybe even have to go to the hospital - said one of the students.
 - How do you weight change of glasses that I had a whole day just to keep going?
 - No! - Students answered distractedly.
 - What you need to do everything to fix it?
 - Just put the glass on the table! - Fun said one student.
 - For Sure! - Happily replied the professor. - To be the case with all of life's difficulties. Think about any problem a few minutes and it will be next to you. Think about it for several hours, and she starts to suck you. If you're going to think the whole day, it paralyzes you. You can think about the problem, but usually it's not leads nowhere. Her "weight" is not reduced. Handle the problem allows only the action. Solve ёё, or set aside. It makes no sense to wear my heart heavy stones that paralyze you.