But enough about easy choices. How come some choices are easy but others are hard? Think about a really hard choice you had to make. Not one like the math one, or the ice cream one. Like, what if you could save one of two people you knew, and you had to choose who to save? Ok, perhaps not that hard, but hard, you know what I'm saying? Go ahead and think. There is no clear reasoning to apply. The right choice is not obvious. But why is this choice hard and the ice cream choice easy?
You may be familiar with the rider-elephant metaphor. Your mind is like a rider on an elephant. The rider is your conscious processes (over which you feel you have direct control); the elephant is your automatic processes (things you 'just do', or internal experiences that 'just happen' to you). The rider directs the elephant, but it is the elephant who does the walking. The elephant is much bigger than the rider, symbolising that most of your processes are automatic and the will is weak in the face of raw desire. (Like all metaphors, this one has limitations, but it is still a good way of talking figuratively about what goes on in the mind.)
I think a choice is hard when the elephant doesn't have an automatic behaviour for the situation and there is also no clear reasoning to follow. The elephant says, "I don't know what to do, rider! Have a look at this. Here are some emotions, here are some memories. Go and get a new way of thinking about this problem. I don't know, maybe read something, or go talk to someone, or just sit there and think it over and maybe something will occur to you." And rider goes and tries to work out the right answer with respect to some deep seeded objective. And then either the right choice becomes clear, or some time* passes and the elephant just chooses. Again, if an answer is logically worked out, the choice is dissolved, and if the choice is "made" then it can only be made illogically.