Capybara
Encountering a capybara remains entirely optional. An estimated 99.7% of humans will complete their lives without ever meeting one in person. Capybara populations face habitat pressures, with numbers potentially declining due to wetland destruction. Climate change models suggest suitable capybara habitat may contract by 20-30% by 2100. The experience of capybara-adjacent serenity requires deliberate effort: travel to South America or Japan, zoo visits, or at minimum, internet access. Nothing about existence guarantees capybara interaction. They are a delightful optional extra rather than a mandatory feature of the human condition.
Death
Death achieves the only perfect inevitability score in existence. Despite humanity investing over 200 billion pounds annually in healthcare and longevity research, the mortality rate remains stubbornly fixed at 100%. From Gilgamesh's quest for immortality to modern cryonics, every attempt to circumvent death has failed. The only certainty in an uncertain universe, death comes for emperors and paupers alike, for the just and unjust, for every creature that draws breath. Even stars die eventually. In the category of inevitability, death stands alone, undefeated and undisputed across 13.8 billion years of cosmic history.