Marcus Aurelius (121-180) was a Roman emperor. I would like to share with you two passages from the book Marcus Aurelius' Meditations.

Never regard as a benefit anything which will force you at some point to break your faith, to leave integrity behind, to hate, suspect, or curse another, to dissemble, to covet anything needing the secrecy of walls and drapes. A man who has put first his own mind and divinity, and worships the supremacy of the god within him, makes no drama of his life, no hand-wringing, no craving for solitude or crowds: most of all, his will be a life of neither pursuit nor avoidance, and it is of no remote concern to him whether he will retain the bodily envelope of his soul for a longer or a shorter time. Even if release must come here and now, he will depart as easily as he would perform any other act that admits of integrity and decency. Throughout all his life his one precaution is that his mind should not shift to a state without affinity to a rational and social being. 3:7

We must take into our reckoning not only that life is expended day by day and the remaining balance diminishes, but also this further consideration: if we live longer, there is no guarantee that our mind will likewise retain that power to comprehend and study the world which contributes to our experience of things divine and human. If dementia sets in, there will be no failure of such faculties as breathing, feeding, imagination, desire: before these go, the earlier extinction is of one's proper use of oneself, one's accurate assessment of the gradations of duty, one's ability to analyse impressions, one's understanding of whether the time has come to leave this life - these and all other matters which wholly depend on trained calculation. So we must have a sense of urgency, not only for the ever closer approach of death, but also because our comprehension of the world and our ability to pay proper attention will fade before we do. 3:1