I an sure you might have heard this many a times but do you follow  
what it says? Do you apply it in your life, in your studies, in your  
work?
Think of ways to do. If a great man said those words then they  
definiely have some worth. Well for studies one of the use is straight  
forward. I had applied it my aesi days where I used my imaginations to  
see all the theory I learnt!!! Thermodynamics, fluid dynamics,  
aerodynamics, principles of  flights, propulsion 1 etc. were some of  
the subjects and topics that I had mentally played while putting  
myself to sleep.
Similarlly finding new connection with known and the new theory, see a  
gas turbine engine work in imagination were some of the things that I  
did.
So during this exam study time see how powerful imagination is. Apply  
it!!