Observation :
You can observe a lot just by watching.	- Yogi Berra: Quoted in Eric Hodgin’s Episode
Innocent and infinite are the pleasure of observation.	- Henry James
Obstinacy :
The foolish and the dead alone never change their opinion.	- Lowell
Opinions cannot survive if one has no chance to fight for them.	- Thomas Mann
Opinion in good men is but knowledge in the making.	- John Milton
Obstinacy is the sister of constancy.	- Montaigne
Opportunity :
Opportunity has hair in front but is bald behind.	- Attributed to Aesop
A wise man will make more opportunities than he finds.	- Francis Bacon
No great man ever complains of want of opportunity.	- Ralph Waldo Emerson