I don't imagine you'll be doing this very often, but maybe you're out of Lessons, so you planned to discard, but some things happened in response, and one thing led to another, and now it's time to learn, but you have an empty hand, and this is all very embarrassing, and let's just not speak of it again, okay
In many decks, Dawn of Hope's other ability is just a bonus, and those decks might hardly even bother with it until they need a mana sink later in the game
The first time I properly met Simon was at Pro Tour Oath of the Gatewatch, where his team, Team Eureka, broke this deck out into the world after previously only being seen as a fringe deck on Magic Online (funnily enough, the CEO of ThreeForOne, Oliver Polak-Rottman, was also part of Team Eureka!)
Overall, Delirium is one of my favorite Magic mechanics of all time, and it's one that I welcome in any Limited or Constructed environment
Flying, first strike Whenever Sidar Jabari deals combat damage to a player, return target Knight creature card from your graveyard to the battlefield
And I didn't even go to many Grand Prix