Comedy came from pain.
A very smart pony had said that once. She, being of average intelligence and above average bounciness, had disbelieved it. Giggles didn't have to hurt, surely? No pony got cut from a whoopie cushion, while words certainly weren't sticks and stones. Until suddenly, they were. The blood wasn't coppery and red, but ponies bled all the same. Their happiness released in arterial sprays, invisible gore coating their lives.
Pinkie Pie had no truck for that.
So she made a vow that day. When Marble spoke for the last time, and Limestone lost her smile. She'd take it. She'd take all of it.
Every pratfall. Every harsh word. Every cut, real or otherwise.
You could flay her alive, drain every last drop of blood, and turn all two hundred and five bones into powder. She'd still be the funniest pony in the room. She had to be.