The point is not when you spend your money but where you spend your money on. You can spend your money immediately but are you spending it on something worth its price? Something valuable? Something that is necessary?
Yes, that is true. You can spend your money instantly, but in worthy things. For an example, when someone is beginning his business, he has to invest money on it to improve the service's quality, and as consequence to maximize his returns on long term. Therefore, he can spend his money immediately on it, because he knows it's going to be useful in order to raise his income from that moment on.
At same time, we must keep in mind it's necessary to keep an emergency fund in every cases, as we never know when we are going to need to pay an extraordinary bill.