“Because he often has an incorrect attitude towards Lent, thinking of it as regulatory-mechanical: Don’t eat this, comply with that, and so on. And then, not trying to change his internal spiritual nature, to correct it, calling to God for help, he tries to curb his passions by his own willpower, but not uprooting them in the depths of his heart, but restraining them somewhere on the surface. Therefore, on the feasts—Pascha or the Nativity of Christ—he removes the bridle from the horse of his body and no longer holding back, rushes off somewhere.”
(Priest Andrei Chizhenko in orthochristian.com)