I think that apostrophes ARE important - they show possession. Take a look at this example:
The girl's bags were big.
This refers to all the bags belonging to ONE girl. But if you move the apostrophe like in the second example:
The girls' bags were big.
This refers to the bags belonging to MORE THAN ONE girl. If you don't use apostrophes, you can lose the meaning of a sentence altogether. I know apostrophes aren't the most vital things on the planet, but hey, if you can use them, do!
