I know that language evolves over time. I know that means that things like spelling and punctuation change. But sometimes, it's really just easier if we follow the rules. I would like to present the following evidence that punctuation can be a matter of life and death:
A panda walks into a cafe, sits down, and orders a sandwich and a drink. After he finishes his meal, he stands up, pulls out a gun, and shoots the waiter. The manager shouts, "Hey! Why did you just shoot my waiter?!" The panda tosses him a poorly-punctuated wildlife manual and says, "I'm a panda. Look it up." So the manager opens the book to panda and reads: "Panda: a bear-like mammal from Asia with distinctive black-and-white markings. Eats, shoots, and leaves." **
Look at the difference between these two sentences:
"It's time to eat, Grandma!"
"It's time to eat Grandma!"
You see? Punctuation makes a difference.
**If you think this joke is funny, read Lynn Truss's book "Eats, Shoots and Leaves". It's an entertaining spin on a punctuation book.