Monday
Monday demonstrates extraordinary predictive reliability, arriving precisely every 168 hours with mechanical precision that would humble the most sophisticated Swiss timepiece. This temporal certainty has spawned an entire industry of anticipatory dread, with Sunday evenings worldwide characterised by a peculiar melancholy that researchers have termed 'pre-Monday syndrome'. The phenomenon transcends cultural boundaries - from Tokyo salarymen to London commuters, the approach of Monday triggers identical neurological responses. Remarkably, Monday cannot be delayed, rescheduled, or reasoned with. It arrives whether one is prepared or catastrophically unprepared. Calendar manufacturers have exploited this predictability for centuries, secure in the knowledge that their product accurately reflects an immutable cosmic truth. Even the most optimistic human cannot wish Monday away, though evidence suggests many have attempted precisely this whilst hiding beneath their duvets.
Waterfall
The waterfall operates within an entirely different predictive framework, one governed by the eternal conspiracy between gravity and accumulated water mass. Unlike Monday, which maintains rigid scheduling, waterfalls exhibit continuous predictability - they are always occurring, never not occurring, perpetually engaged in their singular purpose of falling downward. This creates an interesting philosophical distinction: whilst Monday's predictability involves knowing when it shall arrive, the waterfall's predictability centres on the certainty that it never actually leaves. Hydrologists have documented waterfalls maintaining their descent for millions of years, an endurance record that Monday, despite its persistence, cannot match. However, individual waterfall behaviour varies with seasonal precipitation and upstream conditions, introducing variables that Monday, in its bureaucratic consistency, would never tolerate.