A quote
We are ungrateful for past gains, because we hope for the future, as if the future—if so be that any future is ours—will not be quickly blended with the past. People set a narrow limit to their enjoyments if they take pleasure only in the present; both the future and the past serve for our delight—the one with anticipation, and the other with memories but the one is contingent and may not come to pass, while the other must have been.
Seneca·Letter 99 — On Consolation to the Bereaved (§5)·trans. Gummere