Why hold on when it is better to let go??

Accepted! Perseverance is by far the most important entity required for success. But on second thoughts maybe it! There are times when it is better to let go rather than hold on. Atleast thats what i feel. Dont get me wrong. I dont mean to say that it is heroic to chicken out when the going gets tough. Perseverance takes a lot of courage,strength and confidence. But i believe there are instances when a lot more of the above is required to let go than to persevere. Why? There are times when we obviously go wrong and when realisation strikes its always easier to hold our head high and persevere, rather than question our actions. Its easier to hold on because to let go we need to accept that we have erred. And that is no man's cup of tea. But what's the use of holding on when we are clinging to the wrong branch in the first place? Maybe thats what Peter Drucker had in mind when he said:

"There is nothing so useless as doing efficiently that which should not be done at all".

Progress doesnt lie in simply holding on.... Maybe we should learn to question our beliefs, let go of the past and start anew.... and that isnt easy. There are times when perseverance is foolish... That marriage that isnt working.... That hatred you nurture... That course that we should have never taken up in college... Maybe its high time we let it go and free ourselves.. Obviously there will be people who will snigger behind our backs and call us chickens... Ask them to hold on. They will never understand the power of letting it go......

P.S I aint a self improvement guru. I myself am caught up in a course that i should have never taken up in the first place... and i am still holding on to it for the past four years. So i dont exactly practice what i preach. Havent got the courage to do it either. Letting go i believe is an interesting idea and i felt that i had to put it in writing. I am new to writing. This is just my second post and i aint very fluent in english. This blog is an attempt to improve my english. Looking forward to your comments on how i can improve my writing skills.