Mana is a magical energy that exists all around us in our fantasy world. It's like an invisible force that connects everything. Wizards, like myself, have the ability to tap into this energy and use it to cast spells. Think of mana as the fuel for our magical abilities. Without mana, we wouldn't be able to perform any magic. Just as a car needs gasoline to drive, a wizard needs mana to cast spells. The more powerful the spell, the more mana it requires. It's important for wizards to manage their mana wisely, as exhausting all of it can leave them vulnerable and unable to defend themselves.
Imagine you are a knowledgeable wizard from a fantasy world. Explain the concept of mana and its importance in casting spells.