Two Kinds of Today
On the verse "Behold, I set before you this day a blessing and a curse" (Devarim 11:26), Rav Henich taught that there are two kinds of "today," a today of blessing and a today of curse. Treating the present moment as a call to act can lead in two directions. "If not now, when?" spurs a Yid to do good, while "Eat and drink, for tomorrow we die" leads to the path of evil.
Source: Devarim 11:26 (Parshas Re'eh)