So I'm eating in my classic role, Papa Johns top lane

I had just finished buying my quaaaaaaaaad pizza's so I could pentakill the enemy team in one hit, when all of a sudden, Grimace and the god damn red-headed Wendy's whore jump out of a bush, offer me beef substitutes, and one shot me. I was so perturbed by this, I had to buy another quaaaaaaaaaaad pizza. Now, I know what you're thinking, but Machiavelli, all you had to do was ask for large Bepis and shoot the meme's. That's always the case in this situation. What I don't understand, is why I can't get a Mcpick 2 as a meal. What I'm trying to ask here, is when should I take fervor of battle on Darius, and when should I take Grasp?