A famous author of a widely publicized book advised everyone not to practise the negative way of " I can not do it. But simply say, how can I do it. Why.... Here are my explanations. I hope you can add and share your own experience in life.
What is the effect of the first statement. Since it is a is a declarative sentence, it is an admission that you can not do it and will never do it. You are simply sending a bad message to your brain to stay idle most of the time. Punctuation wise, it is not a comma, but a period.
The second sentence is a question. It will energize your will power and surely you will be propelled to do something, anything and everything. You will even be doing the impossible to get the answer, even risking your health and life just to know the answer. Since it it remains a question mark, you will be looking for the appropriate answer . Conclusion-The "how to do it" solution, which is lurking in your brain" will make yourself on the go. Like the purpose of life, search for it, The "why you are here and for what purpose" would make your life even more meaningful, you will ask God, today and the rest of your life this question. "Lord, why, I am here."
