How heavy would this glass of water be if you were holding it?
The absolute weight of the glass is not what matters. It all depends on how long you hold it. If you hold it for a minute or two, it would be fairly light. If you were to hold it for an hour, its weight might make your arm ache a little.
If you hold it for a day straight, your arm would, more than likely, cramp up and feel completely numb and paralyzed, forcing you to drop the glass to the floor.
Notice in each case, it is not the weight of the glass because it does not change, but the longer you hold it, the heavier it becomes, and that is the way it is with stress. Our stresses and worries in life are much like this glass of water. If you think about them for a while, nothing happens. Think about them a bit longer and you begin to ache a little. Think about them all day long, and you will feel completely numb and paralyzed – incapable of doing anything else until you drop them.
Moral of The Story: It’s important to remember to let go of your stresses and worries. If we carry our burdens all the time, sooner or later, as the burden becomes increasingly heavy, we won’t be able to carry on. As with the glass of water, you have to put it down and rest, drop it, let it go!
— story from lifelords.com