If there are four or fewer cards in the deck then they are still placed in the break zone, but the auto-ability is not triggered afterwards
Unlike a lot of mechanics since, however, Lessons have been featured in a few sets now and have become a big part of competitive Magic
After all, not only are they only available at FNM events, but many may never leave the country
Control decks tend to be safer against Exile and other removal effects, as they rely less on establishing a strong board state with one or more big creatures
And then you can exert it, if you want, to shoot something for another four damage
This deck is very fun for any casual player since it promotes doing things most players find very cool when they start playing Magic: cast extremely big and scary spells