I would add that motive, in the USA, tends to have a negative connotation to it. In other words, motive is a word not commonly used, and when it is it associated with things like criminal investigations. The reasons why a suspect would commit a crime. Motivation, on the other hand, is a word people exclusively connect or associate with positive and good feelings as well as the energy to do something. It's opposites could be laziness, being too tired, lack of desire, or not having good enough reasons to do something.