You can't make a horse drink, but leading one to water may induce it to drink.
You can't force yourself to be happy, but you can set up conditions that induce happiness.
Can you force yourself to solve a problem? Does trying hard make thought work faster? By analogy to physical actions, we would expect that thinking hard would work better than taking it easy. I am starting to wonder if this is a good analogy. Perhaps we can not force ourselves to think creatively, merely create mental states inductive of creative thoughts.
The reason i've been thinking about this is i've been trying quite hard to finish my thesis, and only managing very slow and painful progress. Maybe instead i should set up conditions that afford finishing my thesis, by reviewing the remaining problems i need to solve without actively trying to solve them.
Worth a try.