The simple but observable ...

The simple but observable fact is that the more you love, the more you are able to love.
 Joyce Brothers

Quotes from the same author

Trust your hunches. They're usually based on facts filed away just below the conscious level.
 Joyce Brothers
There's a very positive relationship between people's ability to accomplish any task and the time they're willing to spend on it.
 Joyce Brothers
Women who are confident of their abilities are more likely to succeed than those who lack confidence, even though the latter may be much more competent and talented and industrious.
 Joyce Brothers
Success is a state of mind. If you want success, start thinking of yourself as a success.
 Joyce Brothers
Studies indicate that the one quality all successful people have is persistence. They're willing to spend more time accomplishing a task and to persevere in the face of many difficult odds. There's a very positive relationship between people's ability to accomplish any task and the time they're willing to spend on it.
 Joyce Brothers