Trees don't grow to the sky

I came across this phrase. I admit to do little searching on it just a quick google.
The websites didn't make sense and here I am. Trees do grow to the sky where else would they grow? If you were a giant sure they wouldn't grow to your sky but to a rabbit yes they do. I just find that a bit annoying and yeah I am being preachy. Post a comment if your not happy or would like to shed some light on this phrase.

Pain

Has anyone ever stepped on a thistle? They are extremly annoying pointy prickly weeds that come up in the midst of summer. Just when you want to run through fields barefoot. Some are small unassuming, those are the ones you watch out for.

Yet I wonder would it be better to just run through fields barefoot anyway. Maybe its just the fear of pain that keeps us from doing what we really want. I mean even if there is one nasty bugger in a field. There's probably 100s of daisies.