[31a middle] Rava: Bundles of leaves that are gathered into one place (and accordingly set aside for use) on YomTov are still prohibited to use. Because, they will likely blow away and get scattered by the wind (and then not be contained in one appropriated area and thereby prohibited).
http://blog.genesissports.org/author/rudyb/page/3/?s= E’s Lesson: When there is a strong likelihood for prohibition, it may be viewed as such even preemptively. When should never put ourselves into problematic situations. The Gemarah even describes when one chooses to walk through an inappropriate area to gain reward for beating his evil inclination, he is deemed a Rasha (wicked person). We should never test our fate and always keep ourselves far away from sin. We should place ourselves in appropriate environments to grow spiritually and keep contamination out of our homes.