Haha, there's no obligation, so no need to apologize! My secret agenda is just to get folks outside, enjoying the little beautiful things that you only notice if you take the time to look.
My hope for the challenge was for participants to have a physical journal--one that can be enjoyed and used for reference in real life, not just on Steemit. That way, you can have the proof photo, too! But there's no "requirement" to have a journal. The only request I would have is, like I said in the intro post, some sort of physical representation of your observations with the date. You can even write with a stick in the mud, and take a photo of that!