You find needlessly killed wildlife funny?  When I learned about the issue, I started collecting and using reusable shopping bags.  It took a few weeks to get in the habit, but now I don't even think about it.  I just keep them in my car.  It's easy, you can do it!
Some people need a push to change their bad habits - that's what a tax can do.  If you really want a plastic bag, you can still use one.
"No one knows exactly why caribou and reindeer are so attracted to plastic bags, Montgomery said. She said both the Williams Reindeer Farm and Matanuska Experiment Farm in Palmer discovered this first-hand, after necropsies revealed plastic bag ingestion was the cause of death for several of their animals. "
This is just the tip of the iceberg.  I hope you do some reading up on this topic if you are ignorant of how many animals are killed by eating plastic bags. 
http://www.frontiersman.com/news/mat-su-bag-it-committee-keeps-pushing-forward/article_26fffa4c-d813-11e6-baa2-db2ebad70750.html