"It is better to be the hammer than the nail."

Tonight I spent a rewarding evening with the women who took me out to the Mandarin for my birthday and the Chinese Proverb cookie I opened said: “It is better to be the hammer than the nail." The closest to this saying is a quote from Emily Dickinson who said: ” “It is better to be the hammer than the anvil.”

I Googled it and the variations are also interesting:

Quotes on the hammer and the anvil:

“One must either be the hammer or the anvil.”

“The anvil is not afraid of the hammer.”

“You must either conquer and rule or serve and lose, suffer or triumph, be the anvil or the hammer” 

“The anvil lasts longer than the hammer”

Anyone want to suggest their meaning?

Or give examples of real life situations of the hammer or the anvil? 

When is it better?

When is it worse?

Is it true that the hammer is not afraid of the anvil? 

When is this true or not?

Are there only 2 choices: the hammer or the anvil? 

Are there more choices? 

Are these sayings related to "fight or flight" or something else?

When does the anvil last longer than the hammer -or does it?

Here's a similar discussion on Albert Einstein's famous quote: 

“If you judge a fish on its ability to climb a tree, it will forever think it’s stupid.”?