I think if you are doing things just to keep yourself busy or self-focused stuff like learning a language or playing an instrument, you will eventually hit the wall of motivation created by lack of necessity when your financial needs are already met forever. Definitely do them to keep life interesting but don't expect that much from these activities (unless you are like crazy passionate about any of them, in which case, congratulations, you found your true purpose).

I believe you'll need to have goals that involve improving lives of those that most need it. Of course it is more complicated than just that - there will be disappointments, betrayal and all other stuff that comes with getting other people involved but the key is to do it based on purpose, with a calm head, clear goal and less on fumes of emotion to manage such pitfalls better. You can let that emotion out when you see the unprivileged child you mentored succeed - I would wager that that moment will outweigh practically any joy you could feel from solely self focused achievements.