I couldn’t care less. Learn to write and say it correctly.
I could care less means; you have some room to care even less; you could care less, but you still care a little.
I couldn’t care less means; there is no room for caring; you could not care less. You have reached the bottom and now looking up into caring. All the care in the world is beyond your reach and you no longer have the slightest bit of compassion. You could not be moved emotionally on the issue even if a large trout about the head and shoulders were to be applied vigorously. You do not care. You have given up. You officially don’t give a damn.
This has been a public service announcement.