Know well that you are mortal

Things as tru today as 2,500 years ago.  From a Greek epitaph.

εὖ εἰδὼς ὅτι θνητὸς ἔφυς σὸν θυμὸν ἄεξε,

τερπόμενος θαλίῃσι· θανόντι σοι οὔτις ὄνησις. 

Know well that you are mortal: fill your heart

By delighting in the feasts: nothing is useful to you when you’re dead.