it's better to assume that people will simply do everything that is possible, you can't open umbrella in your butt so that can be assumed not to be done, but ev

it's better to assume that people will simply do everything that is possible, you can't open umbrella in your butt so that can be assumed not to be done, but everything possible should be assumed done/to be done sonner or later; motivation of "because I can" is simply enough.