It's surprising, really, how much little things can matter. A good example is one teachers use to stress the importance of punctuation--the difference between these two sentences:
Let's eat Grandma!
Let's eat, Grandma!
The comma is just a tiny little spot of ink (or pixels!) but it changes the sentence dramatically.
Many years ago, some of the relatives were together for Thanksgiving and we were playing Pictionary. My teammate was drawing a man in striped clothing, and I was guessing words like "convict, prisoner, criminal, inmate".
The right word was "umpire". The direction of the stripes made all the difference.
And then one day I answered the phone at the insurance agency where I worked. The man on the other line had a fairly strong accent, and he asked if he could "Make an appointment to have a look at Debbie."
"Pardon me, sir? Have a look at Debbie?"
"Yes. I need to look at Debbie."
In the background someone said something and he returned to the phone, "I need to see Debbie."
OH! Well. That sounded much less creepy, even though having a look and seeing are practically the same idea.
How easy it is to miscommunicate what we really intend, all because of a stripe, a comma, or simple semantics.