When you frustrate someone, you do your best to annoy, confuse, or even torment that poor person. Maybe you constantly change your mind — that's sure to frustrate anyone who tries to make plans with you.
If you have ever been frustrated while writing, you may have dropped your pen — or pushed away your keyboard — and stared angrily out the window, thinking, "How will I ever do this?" Well, that pent-up doubting that has made you stop is a sure sign you are frustrated. Plans, too, can be frustrated, like the snow that frustrates our efforts to run our errands.