Motivation and determination for anything comes from within. One can not barrow it from someone else.
Success is working with enthusiasm and ambition, living with joy and kindness, and going toward a life of ultimate service and happiness.
Your youth is certainly finished and old age has definitely arrived if you feel that you are losing enthusiasm, excitement and energy towards your dreams and goals.
I never think of him as a scholar assaulting me with how much he knows, but as a teacher eager to share a lifelong passion for the subject.
The volume of your impacts is measured by the direction of your movements, the passion with which you inspire and the attitudes by which you make an influence!
Teddy Roosevelt "had relished "every hour" of every day as president. Indeed, (he was) fearing the "dull thud" he would experience upon returning to private life.
I would not be among you to-night (being awarded the 1964 Nobel Prize in Physiology or Medicine) but for the mentors, colleagues and students who have guided and aided me throughout my scientific life...
Entrepreneurs don't have weekends or birthdays or holidays. Every day is my weekend, my birthday, my holiday. OR, every day is my work day. Mostly it's a choice.
You can not have empty or neutral mind, as long as you work the mind will contain dreams, if you stop working it will contain regrets.
Nevertheless, scientific method is not the same as the scientific spirit. The scientific spirit does not rest content with applying that which is already known, but is a restless spirit, ever pressing...
If you have no good drive in you, your life will not be steered through a good direction. It will miss its destined station. Passion or drive is what moves the vehicle of a fulfilled life.