Gandhi isn't merely reminding us that we can't change the past or predict the future—he's pointing out something subtler: we waste the present moment *pretending* we can do something about those unreachable days. A person ruminating over a failed job interview five years ago, or anxiously planning contingencies for a career move still months away, is squandering the very hours when they might actually prepare, heal, or take action. The insight that bites is that regret and anxiety are luxuries we can't afford, not because they're emotions we shouldn't feel, but because they cost us the only day that was ever truly ours to work with.