For most people, we're told from the very beginning to aim for the sky when it comes to goals. "The sky is the limit", we're told. When you're a child, this sounds amazing because you can't comprehend the scale these phrases imply. But we're (at least I assume) adults. Aiming for the sky is all well and good, but chances are you'll not make it that far - at least not in the short run.
It's not to say that you'll never make it there, because maybe you will. Maybe you'll go beyond that (space?). Or maybe you'll fit in with the rest of the "average" population. Remember: Average is not bad, it's average. Average is okay. If average were bad, then what would failure be? For that matter, failing isn't always bad either, but that's a topic for another article.
Humans, by nature, tend to measure progress as they go, even if not intentionally. Huge goals are fine, but until a goal is met, you might not view it as progress - no matter how much you try to convince yourself otherwise. To apply the example here, the goal should not be "To learn Japanese". If it is, about 2 months in you'll be wanting to give up because you have no way to track your progress. Don't bite off more than you can chew - the rest will still be there for you tomorrow.
Rather, I prefer to use what I call "stepped aiming" - the notion that the higher you go, the higher you can aim. So, instead of "to learn Japanese", your immediate goal would be "learn 100 kanji", then 200, 500, and so on. The idea is that you set attainable, short term goals. This not only a great way to measure progress, but it gives you a sense of accomplishment as well. It also serves as motivation to keep going. It makes the big picture look... not so big.
Keep this in mind as you proceed not just with learning Japanese, but anything in life as a whole.