Setting Unrealistic Goals: An Example

I am a goal setting fiend. Give me an idea, I'll set a goal for it. Unfortunately, I am not a goal accomplishing fiend. Quite the opposite. And one of my most recent goals is already looking to be one of the goals I'm pretty unlikely to see through, but not because I don't want to.

I have been using Khan Academy's excellent mathematics video library and practice problems since I hit secondary school. I love how well the concepts are explained and drawn out for you, and have often felt that were it not for Khan Academy, my love for math would never have blossomed the way it did in high school. 
Recently I had the bright idea to attempt to complete ALL mathematics pathways on Khan Academy, from Pre-K basic concepts through to Linear Algebra and whatever else they offer. I'm sitting firmly in the 5th grade arena at this point, not struggling, but definitely overwhelmed by the reality of  just how much time this will take. 
After a little googling I discovered that one man said that he was able to complete the entire mathematics pathway in just over 150 days. Nearly half a year. And that was with him dedicated pretty much all of his free time to it! (I'm giving it maybe a few hours a week)
So... I'm not too sure if this is something I'll actually finish out before summer because I'm fairly certain that it's simply not possible for me to do it in that amount of time. But I guess we'll see what happens!