This is a saying Ive used for a long time now, basically if you compare exp per session of someone that has sat their grinding 2moons dil constantly for 3 hours to someone who is doing a lot of quests that involve killing X mobs or getting item Y from Mob Z youll find that the person that does the quests has a greater amount of exp gain, why, because quests give you exp, mobs give you exp also, so combining them gives you the greatest amount of exp compared to grinding alone. That and its much less boring.
A heros available Inspirations are displayed in an Inventory Tray located above the Power Tray. After an Inspiration is used, it is gone forever and disappears from the Inventory Tray. Use an Inspiration by clicking its icon in the Inventory Tray. You can also use the bottom row of Inspirations by hitting the corresponding function key, starting with F1. To keep your Inspirations organized, you can click-and-drag them to different slots in your Inventory Tray. Click the arrow icon on the Inspirations Tray to display additional rows of slots, or click it again to collapse the window to show only the bottom.