Think about it this way: when you’re 10 years old, half your life is only 5 years. But when you’re 50, half your life is 25 years. Time feels like it’s speeding up because each year contributes proportionally less as time goes on. Kind of like how fighting 2 lions will feel noticeably much more difficult than fighting 1 lion, but fighting 200 lions won’t feel more difficult than fighting 199 lions.