To burn the midnight oil !

Meaning :" To work or study very late at night"
Alternative way to say the same thing:
1. " Stay up"
2. " Pull an all nighter"
3. "Cram"
Situation when this idiom would be used:
" We burned the midnight oil for three nights in order to study for the quiz."
The people I interviewed:
1. Dr.Richard Smith ,he's dentist for 38 years,he's from Auburn but he is working in Citrus Heights.Dr. Smith's explanation for my idiom was:
"To burn the candle at both ends"- that means :
"To work or study to hard without enough rest".
Dr. Smith had burned many candles when he was student at college.
2. Dan Levin he is a manager of the dental office and he is a husband and father of two boys,and a coach of a highschool footbal team.
"He burn a lot of midnight oil when he is working on the new game strategies for his team."
3. Joyce Scott she is dental hygienist for 16 years,she's also a mother of three children,she is burning the midnight oil to do the house work.
I have learned from this interview experience that:
*An idiom is a combination of word that has a meaning that is different from the meanings of the individual words themselves.
*Many idioms are similar to expressions in other languages and can be easy for a learner to understand.Other idioms come from older phrases which have changed over time.
So:
" To become a good ESL student ,you have to burn the midnight oil"