On the half nobody quotes
“Seize the day, trusting as little as possible in tomorrow.”
Carpe diem has been worn down into an invitation to spend money. The clause after it is what Horace actually wrote, and it changes the temperature entirely.
Trusting as little as possible in tomorrow is not an argument for excess. It is an argument against deferral — against treating the present as a corridor to somewhere better and spending it accordingly. The poem is addressed to a woman who has been counting on years she may not get.