The Purpose of Your Intent
When someone says it quickly, “for all intents and purposes” does sound like “for all intensive purposes.” The former phrase is correct, and it indicates you cover all possibilities and circumstances in a situation or scenario.
Caring Is Sharing
If you want to express your feelings of complete apathy, you might say “I couldn’t care less.” When you say “I could care less,” you actually talk about some minimal level of regard you show for someone or something.