So you want to learn Japanese? Excellent. However, you need to keep a few things in mind.

Mastering a language takes time
We're talking serious time too. Of course, some methods of learning will be faster than others. The methods listed here should help to fast track your progress. Nevertheless, we're still talking truck loads of time.

Perhaps you're thinking, "I'm no good at languages". I would suggest that instead you may be:

1. using ineffective methods of learning; and/or
2. investing insufficient time into your language learning

Alternatively, if you think you're too old to learn to Japanese, quickly jump into a cold shower, slap yourself in the face, then read You're not too old.

Learning Japanese will require you to think differently.
One of the biggest hurdles when learning a second language, Japanese in particular, is learning to think differently. I'm not just talking about getting your head around the different word order, putting verbs at the end and all that. I'm talking about weird concepts like in-group and out-group, hierarchical relations and the suffering passive.

Common reactions to having to think differently are:

That's dumb!  That's bad!  That's wrong!

Whatever. The fact is the more tolerant you are of different ways of thinking, the more willing you are to try things on, the easier you'll find Japanese to learn. If you think it is "bad" to, for instance, think about people in terms of whether they are junior or senior to you, then you'll immediately sabotage your language learning.

However, be warned. Learning different ways of thinking does not equate to becoming Japanese. You are not learning Japanese to become Japanese! I assure you that the better you get at Japanese, the more confused you'll become about this point. For a deeper discussion of this, go to Don't become Japanese.