Laudator Temporis Acti

Augustine, Letters 213.1 (Corpus Scriptorum Ecclesiasticorum Latinorum, vol. 57, p. 373; tr. Sister Wilfrid Parsons):

In this life we are all mortal men and the last day of this life is always uncertain for every man. In infancy our hopes are fixed on childhood, in childhood we look to adolescence, in adolescence we look forward to manhood, in manhood to middle age, and in middle age to old age. Whether this will be our lot we do not know, but it is what we hope for. Old age, however, has no other period to expect. How long old age itself will last is hidden from man, but it is certain that there is no other age to follow old age.

omnes in hac vita mortales sumus, et dies huius vitae ultimus, omni homini est semper incertus: verumtamen in infantia speratur pueritia; et in pueritia speratur adolescentia; et in adolescentia speratur iuventus; et in iuventute speratur gravitas; et in gravitate speratur senectus: utrum contingat incertum est; est tamen quod speretur. senectus autem aliam aetatem quam speret, non habet: incertum est etiam ipsa senectus quamdiu sit homini; illud tamen certum est, nullam remanere aetatem quae possit succedere senectuti.