Learning the keys is a journey, timbass, but if you practice 1 or 2 hours a day and have the proper direction in your practice, you will almost certainly make the trip. Note proper direction. Personally, I think that a person who practiced 1 or 2 hours a day as a true and sure thing would have a hard time not succeeding. The trip would seem arduous and slow and you would think you weren't progressing at all sometimes but you would be.
Be aware that sometimes progress comes in sudden bursts. You practice something for a while and you can't get it, and suddenly after you've almost given up, voila, it's under your fingers.
Being led by a teacher at first, or a friend who has made the journey so that your practice will be proper helps, but many do it on their own.