Squeezing through

That photo reminded me of an epiphany. I was driving around the country roads of Northern Ireland where I presently reside, and seeing for the umpteenth time, a sheep with its head stuck through a wire fence dividing a farmer’s fields. Why ? Just because the grass was greener ? No, that was a human view. I saw it or thought I did from the sheep’s mind.
Why was the fence there other than to draw attention to the fact of its existence as a barrier to be breached ?
Thanks for this memo Michael.