Originally Posted by
Jeeqbit
Why would you not remember to look? The game tells you about it in Active Help, it adds the actions to your hotbar when you level up and it's generally obvious that if your hotbars are a mess because you just returned, you should look at finding the menu that allows you to redo them.
When you return to the game you get invited to the Novice Network where you can ask these sort of questions if you are lost, or you can ask in your free company chat if you're still in one.
Some people may not want actions on their hotbar because of them being useless or impractical and this helps SE to know when an action has fallen out of use, which does usually happen to a small number of actions or abilities each expansion.