There was once a revered old monk in a monastery. Every day he went out and took care of the garden. He didn't shy away from hard work despite his age. The other monks worried about him and one day decided to hide the shovel that he always used for his work. The monk said nothing and stopped working just as the other monks had hoped he would. A few weeks later he died!
It appears the monk took the missing shovel as a sign from above to just let go. Catering to the garden had given him life's meaning while without it nothing could keep him on earth anymore. That is exactly how death works - it is a decision. For most of us these changes happen subconsciously and we experience death as an event beyond our control. But for some big souls it can be an active choice as well. Nothing is really strong enough to beat us, but when we hear the voice inside that it is time to let go, we do sooner or later.
Viktor Frankl in his book Man's Search for Meaning had a strange observation that confirmed this thesis. During his stay in a Nazi concentration camp he noticed that whenever someone was found smoking a cigarette, that person would often die within a few days afterwards. During those times cigarettes acted as currencies, so lighting a cigarette meant that you were literally setting money on fire! Frankl took this as a sign that they had simply given up on life. Conditions were so so tough during these days that only a strong will for surviving gave you a shot of making it to the next day.
Sun Tzu once claimed, "victory is reserved to those who are willing to pay the price." Well, we are that powerful, we can accomplish whatever we set our heart on. But then there are the times when we are unwilling to pay the price. That's when we are ready to move on. How do we know when it is time to fight and when it is time to move on, you might ask. Well, that depends on your mission in life. As long as you have one and are willing to see it through no matter what the price, no one can keep you from it.