When ideas run dry

Don't you hate it when you try to think of something to do but never can because there is nothing to do. Well i face the samething and it annoys me sometimes. Its hard to give me a motivation because when you try to think its like nothing. When you see a student who does all his work and seems like hes doing nothing don't blame him hes just running dry and is stumped on what to do next for example after you finish doing whatever your goal is you don't know what to do next.