“Where am I when I really need me?”

“Play stupid games, win stupid prizes.”

“The beatings will continue until morale improves.”1)

“I have concepts of a plan.”

“That didn't happen.
And if it did, it wasn't that bad.
And if it was, that's not a big deal.
And if it is, that's not my fault.
And if it was, I didn't mean it.
And if I did, you deserved it.”2)

“Yesterday's future is today.”3)

“The storage for fossil fuel waste is your lungs.”4)

“My first victim was myself.”

1)
In conjunction with “Morale will not improve until the beatings stop.” | Other words can be substituted for “beatings”.
2)
Oftentimes shorted by a few lines.
3)
South Park S5 E13, “Alder Research Group” van at 01:53
4)
As a response to nuclear fuel waste.