There are basically three motivating factors. Internal motivating factors are personal needs, and a range of emotion drive it.   Love, happiness, jealousy and anger can all be internal motivating factors.
Doing something to make someone happy or to receive recognition is an external motivating factor. Perhaps I see an opportunity at work to move up or to receive a promotion and holding me back is the lack of a degree.   The opportunity to advance is an external motivating factor, but I need the internal motivating factor to push me to pursue the college degree and realize the opportunity.   This melding of the need of opportunity and the internal persistence to obtain the tools to reach it is a blended motivating factor.
Initially, I thought what motivated me in childhood certainly does not motivate me now.   As a child, I was motivated to get out of bed early to go play baseball, because I wanted to be picked to play.   Now I get up early to go to work so I can keep my job and be picked to move up in the company.   Analyzing this, I realize the motivating factors are the same.   In both situations, as a child and adult, I am looking for acceptance and/or recognition. Acceptance and recognition are motivating factors at every stage of life.
In my early twenties I had a sever accident while working a summer job.   After awakening in a hospital, I was told that due to a spinal injury there was a good chance I would not walk again. That night my internal and external motivating factors were strong.   The sound of my parents weeping in the hospital hallway made me sad, and my sadness turned to anger, and my anger turned to determination.   After everyone left for the night, I made myself get out of bed and made my legs move.   It took nine months, but I was able to walk out of that hospital and I have never looked back.
I got married and had children. Love for my children continues to motivate me to try to provide the best for them.   It makes me feel good to see them...