Life is like riding a bicycle. To keep your balance you must keep moving.

· Albert Einstein

Great things are done by a series of small things brought together.

· Vincent van Gogh

No man ever steps in the same river twice.

· Heraclitus

Progress is impossible without change, and those who cannot change their minds cannot change anything.

· George Bernard Shaw

If there is no struggle, there is no progress.

· Frederick Douglass