Which hobby/project should I choose

Over the past few weeks, I've been thinking a lot about taking up an independent project or a hobby. I seem to have more free time than I know what to do with.

I've brainstormed a bunch of ideas, and four in particular seemed to resonate with me. The problem is that I like all of them equally, and I can't figure out which to do first.

The point of this is to get my ideas out of my head, and to get some feedback. I'd appreciate hearing your thoughts. =)

So without further adieu;


Idea the First!

Writing a completely original mythology.

Pros:

- It's something that I've wanted to do since I was a kid.
- It requires no extra resources or talents, just time and patience.
- The scope of this idea is reasonable condensed... Unlike Idea the Second! and Idea the Third!, there is a good chance that I could finish this one.

Cons:

- I only have a few very rough ideas.
- Coming up with something original will be very difficult (I'm not much of an idea man).
- While not outright bad, I'm not a particularly strong writer.


Idea the Second!

Creating a video game that incorporates classic RPG elements within the game of chess.

Pros:
- I think that this game has the potential to be very fun, both to make and to play.
- This project is huge, and will help me occupy my time for months, if not longer.

Cons:
- This project is huge! There is a good chance that it will end up abandoned.
- If I were to make it, I would want to do it in 3d. I have very limited experience with 3d modeling, and next to none with 3d game engines.
- There are a large number of elements to this game that I have no clue how to do (i.e. sound production, 3d animation, etc.) I would either have to learn a lot of new skills, or I would have to find people who already know how to do these things.
- There is a potential for this project to cost a fair amount of money (i.e. server, software development kits, professional consultants, etc.)


Idea the Third!

Summary: A massive 'choose your own adventure'/text-based rpg.

Pros:
- This sounds like a great deal of fun. I get excited just thinking about this. =P
- The technological requirements and know-how are very practical. Programmatically, I already have the ability to make it. I won't have to learn anything new.
- This requires no graphical elements which will drastically reduce development time.
- If I were really crazy, I could combine this idea with Idea the First!.

Cons:
- Despite the technological simplicity of this idea, it is by far the biggest and most ambitious of the four ideas. After each scene, there needs to be a handful of potential choices... ideally, I would cover all the choices that a person could reasonably make. Each one would have its own fractal outcome. Each main quest line would, essentially, be dozens of novels rolled into one. This will either take me years to do right, or I need to consider accepting third-party story line submissions.
- While not outright bad, I'm not a particularly strong writer.


Idea the Last!

Summary: Learn how to read sheet music and how to properly play the piano.

Pros:
- This idea is the simplest.
- This idea is the most achievable.
- This idea is the most realistic.

Cons:
- This idea is the least exciting to me (don't get me wrong, I would love to learn to play the piano properly, but the other ideas are just so much more exciting...)