Wise words from Aristotle (is there any other kind?): it's way better to be reckless than to be a pleasure-seeking hedonist.
In other words, it's way better to eat an entire cake because you think "Yikes! I heard that there was a local baker's strike. It's probably my only time everagain to eat chocolate cake" than to just lie back and think "Mmm. Cake. Cakeity-cake-cake-cake. So good."
Here's why: Aristotle explains that those who lack self-restraint because of "spiritedness" (basically: becoming enraged or impassioned) aren't quite so bad as those who can't control themselves due to desire.
He describes the spirited person in this way:
For spiritedness seems to hear reason in some way, but to mishear it, like swift servants who run off before they hear what is said in its entirety and then err in carrying out the command... (7.6.1149a27-29)
So the person who's got his blood up does engage with reason—just under the wrong assumptions. The image of the "swift servant" is a pretty awesome simile for the process of becoming impassioned or enraged: we perceive something that we interpret in an unfavorable way and then react before processing the data correctly. Our emotions and physical responses fly in every direction without any deliberation—you know, we hear "baker's strike" and we think "oh no! no more cake ever again!"
While Aristotle says that this kind of behavior is less shameful than simply indulging in our longings it's still hugely problematic. You should slow down and look before you leap.
After all, just check out what happens to Oedipus when he acts before thinking.