meaning - Does さえ mean "even" in the following sentence?

I encountered the following on our daily reading.

どのような企業{きぎょう}も、創業期{そうぎょうき}には全社員が昼食をとること さえ 忘れてしまうほど、忙しくフル回転していたものです。

In a business, a person was so busy that he forgot to eat lunch even lunch. (Not sure if translation is correct.)

From what my friend explained, the さえ means "even" or similar to ほど. Using a similar sentence he explained that さえ was only.

私はお酒 さえ あれば、幸せです。

Even if I have I only have sake, I am happy.

How is さえ used? I think it is synonymous to ほど.

Answer

さえ is similar to も for many cases. It means "even".

どのような企業も₁、創業期には全社員が昼食をとることさえ₂忘れてしまうほど₃、忙しくフル回転していたものです。

• Even(も₁) for any enterprise in its establishment period all the workers are so busy in full operation to the extent(ほど₃) that they will forget even(さえ₂) to have lunch.

However there is a special thing that さえ does when used with a conditional clause. When in a conditional clause it expresses "If only", "as long as".

私はお酒さえあれば、幸せです。

• 
  

  If only I have sake, I am happy.

  
  


• 
  

  As long as I have sake, I am happy.

  
  

Do note that さえ with a conditional clause happens most with ば-conditional, and less frequently with たら-conditional and なら-conditional, and never with と-conditional.