You are dying a little every day, so stop postponing life

Seneca opens his very first letter with an almost violent reframing of time: it isn't that death arrives at the end of life, but that each passing day is itself a small increment of dying, since that day can never be lived again or returned to us. Most people, he says, guard their money and property jealously while letting time — the only truly irreplaceable resource — leak away on things they'd never willingly trade a coin for.

He's especially scornful of people who plan to "really start living" once they retire, hit some milestone, or finish some obligation, since that plan assumes a future that isn't guaranteed and treats the present as disposable rehearsal. Old age arriving is not, to Seneca, actually the tragedy people fear; the tragedy is arriving at old age having never truly lived at all.

Takeaway: audit how you spent your last week the way you'd audit your bank statement — you'll likely find far more waste than you expected.