One of my linked-in connects messaged me after going through my profile and asked me how do I get so much of self motivation . He says he is unable to work hard or strive for something and he is surprised to see my achievements. He asked me my secret of success and secret of energy.  Well, I don't know the answer. I guess it's my manufacturing defect that I am super enthusiastic, positive and self motivated! ;) and I don't think I can cure this defect easily! ;)
Jokes apart.. I think there is a subtle stretch between success and failure. Most of us quit at the beginning  of failure . Whereas success -seekers go beyond their limits to achieve it. And the best part of success is that  even a small success gives us confidence to stretch our limits and do more. It's like this: achievers are always unsatisfied with whatever they achieve.  Once achieved , the achievement becomes small and they set higher goals. This reactivates the cycle of self motivation. Its like an addiction. Simple but effective cycle!
And yes, the irony is that its the same cycle for failures as well. Most people when faced with failure stop doing and keep thinking about failures and lose their confidence. This further leads to setting of lower goals and lower ideas. The problem with lower goals and lower ideas is that there will too much of competition since vast majority of people will be there - in their comfort zones. Then, again, the chances of success are lower and then again you end up as a failure. You lose your self motivation. The cycle continues! Simple. 
Now, coming back to how I am motivated. I would say I was fortunate to get mentored by best mentors right from my childhood - right from my mother who always said that "You need to leave a legacy , when you leave the world" to all my teachers and trainers in school, college, NCC and my early career who instilled in me an urge to strive for higher things rather than for mediocre. Yes, I attribute my achievements to all those trainers and mentors who nurtured my capabilities and removed my insecurities at the time of my failures. And yes, I should also say that I have failed numerous times and the only difference is that I rose up from those failures thanks to their guidances.  
I think, every citizen of the world can be motivated  towards right things and success if he gets the opportunity to get mentored and trained at the right age. The role of a great teacher / trainer/ mentor/ coach /guide is hence of utmost importance in every child's life.

Yes, one more thing- Achievements happen only when you are passionate about the job you do. Passion comes when you do things you love to do and when you do things which makes you happy ! 
Work passionately on things that make you happy , the results are all your achievements. 
Until next, 
CeeVee
P.S: The above simple personal notes do have significant theoretical background . The Self theories by Carol Dweck which says about Incremental Self is an empirical proof of the above success formula.Read more here.. http://www.learning-theories.com/self-theories-dweck.html
Similarly, the theory of meaningful progress - a practical and powerful self-motivator is detailed in the HBR article https://hbr.org/2011/05/the-power-of-small-wins