A Silly Poem

Every time I go to Blakeney for my morning newspaper I pass this bench and always notice the silly poem that someone has pinned to it.  As there was a light covering of snow this morning it wasn’t quite as legible as normal but, courtesy of Spike Milligan, it reads:

Said Hamlet to Ophelia
I'll draw a sketch of thee.
What kind of pencil shall I use?
2B or not 2B?

I quite like that someone took the time to type this out, laminate it, and pin it to a bench, but I also wonder why?