Thermodynamics is HARD - maybe you are good at it, but it was a struggle for me ... just my $.02 ..
The British scientist and author C.P. Snow had an excellent way of remembering the three laws of thermodynamics:
You cannot win (that is, you cannot get something for nothing, because matter and energy are conserved).
You cannot break even (you cannot return to the same energy state, because there is always an increase in disorder; entropy always increases).
You cannot get out of the game (because absolute zero is unattainable).