1. I made a human mage and thought that the way to level was to kill critters and other mobs in Elwynn Forest. After a while I stopped leveling and gave up because I didn't get it.
2. I went to Goldshire and stood there admiring all the cool level 70s. Only problem: I was on a PvP server.
3. On my first ever hunter, I dismissed my initial pet thinking I wanted something cooler, but then I was unable to tame anything because of my low level.