בבוקר תאמר מי יתן ערב ובערב תאמר מי יתן בוקר מפחד לבבך
Rashi explains this practically, with conditions deteriorating on a daily basis to the point that the anguish of today will be so painful it will make one yearn for the suffering of yesterday. This can also refer to those who wake up too late to realize that the life which they led yesterday (in the past) was the precursor to the tzaros, troubles, which they experience today. Whether it be satisfaction with one’s personal spiritual growth or the lack of nachas, satisfaction and pleasure, derived from one’s children – nothing happens in a vacuum. The decisions that we make today…