Is there a kinder way to say "I know"?

"I know" is a ubiquitous statement commonly said in English. However, in some applications, it can be too harsh, or come off as rude.

For example, let's consider the following interaction. "Hey, Kyler, the Butterfly Festival is tomorrow." "I know, Finn." Phrases like "I understand" can be too formal and out of place, and "Thanks for reminding me" is situational and can only be used in instances similar to that.

I was wondering if there was a more polite, friendlier way to say the phrase whilst conveying the same meaning and can be used in any circumstance that "I know" can be used. Any thoughts?

You can always be more specific about how you know:

• "Oh, yes, it's on my calendar."
• "Thanks, I saw the article about the Festival in the Times this weekend."
• "You know, my little sister has been talking about nothing else all week."

And so forth.