Motivation in language learning isn't what people say it is. Motivation as a general rule in fact is a great inner strength that everybody gets endowed with at birth BUT its number one feature is that it comes and then it goes. Motivation does come included in the package at birth, but in fact you don't get to keep it that easily, tightly fastened next to your heart. It doesn't stick around for long, never ever. You have to renew it by visualizing the results you want to obtain. You have to find it again by remembering the last time you made progress towards your goal. You have to chase it over and over again, every day. It's a sad truth, but it's the truth.
As far as learning a language is concerned, well, it takes time and efforts. If you want to learn Norwegian in three months for example, you most probably will be able to do it, but you'll however have to squeeze many hours of studying within those three months. No magic involved; it's hard work and motivation won't be enough whoever you are or think you are.
Now, one happy truth : what all motivated-looking people really have in common is one good habit to start with. What gives those lucky people the energy to work hard and for a long time is not thinking about when they'll have accomplished their goal (even though it can help) nor being naturally helped out by some mysterious self-refueling inner power. They stay consistent because they have at least one good habit in place. They don't need to re-motivate themselves over and over again, they just stick to their schedule. You can do that too !
Here is how to create your first language learning habit. Let's say you want to learn Arabic. The three simple but necessary steps you need to go through are the following :
#1. Decide when you want to learn Arabic five minutes a day every day, without exception
Take this decision in less than 15 seconds. Don't take more time to decide but really do it. After a few days, if you end up not sticking to the habit, take 15 seconds more to decide on another time in the day when your five minutes will better fit in. Do it methodically and you'll eventually find the right time for you.
#2. Plan in advance
Set up your wristwatch alarm to the time you've chosen and have your Arabic book ready.
#3. Do it !
Don't think anymore, open up your book and start reading. I repeat : DON'T THINK ANYMORE, ACT ! Simply direct your eyes towards a page of your book and let them glide from right to left (yeah, that's Arabic you're learning, remember ?)
Let's recapitulate. You were born with motivation but motivation doesn't like to stick around anybody for extended periods of time. Whether you want to learn Arabic, Russian or Amharic, what you really need is habits. As the drawing at the top of this page says, motivation makes someone feel great and it is very useful, but it goes on vacation much too often. Habits stay. They are your true best friends.
And by the way :
5 minutes of language learning per day are enough and will allow you to hold the efforts on the long run !