If you were merely wandering aimlessly with the hope of encountering a grocery store, it would only affect your chance of ending up there insofar as you'd intentionally stop looking if you arrived at one, and not if you didn't. But our grocery seeker is not operating in a complete absence of evidence with regard to how to locate groceries, should they turn out to exist, so the search is, if not well focused, at least not actually aimless.