Love of duty makes sense

Love is a better teacher than a sense of duty.

- Albert Einstein quoted in "How to raise a creative child"

Change

Following quote from Federer helps prove that Change is the only constant.

Lets assume that there is a constant different from change. It there exists such constant, it will start moving backwards which implies change. Hence proved that change is the only constant :D

Staying the same means going backwards.

- Roger Federer