Sadly, many charities are borderline fraudulent. Always ask what their administration fee is. I remember getting a call on Memorial Day asking for donations to veterans. I asked what the administration fee was and he said 90%. I said, "No, I mean what do you take to process these payments and make the calls?" He repeated, "90%." I was floored.
Anyway, to answer the OP's question, you need to save at least some of it. Just because you are making money now doesn't mean you will make it in the future. Plan for a life-changing event where you are unable to make money, or even worse, you are reliant on others to take care of you. Best to have something stored away, preferably an appreciating liquid asset so you can get to it fairly quickly.