Sometimes we plan the week, in precise, efficient detail, and then, a cold comes knocking on the door changing everything. Life is not linear.
And if you force it as such, the joy and spontaneity of the game, the game of life vanishes. Life is just one giant improvisational game, ephemeral and hardly meant for seriousness. The mood of the moment or time might feel grave, but mortality is our constant reminder; this is fleeting, don't be a jerk about it.