"Everyone hurries his life on and suffers from a yearning for the future and a weariness of the present. But he who bestows all of his time on his own needs, who plans out every day as if it were his last, neither longs for nor fears the morrow."
This is the gist of the essay. I don't know, I find it terribly vague and subjective. Seneca defines 'waste' as not living in the present and doing things for others as opposed to, for yourself. Is there a right or wrong way to live? I'm not so sure. I think you should live the way you want, complain about the shortness of life, be idle, do nothing, if that's what you really want to do. The only restriction is not to impose on anyone else's quality of life or right to live the way they want. I would argue Seneca is trying to impose, as am I.