Hi Violinist
I liked you playing in Utube. How long did you practice for this sonata to play at that tempo?
Keep on practice 
Hello Tsagari,
The more I listen/watch my youtube attempt the more I dislike it. The tempo to me seems too fast. I worked today with my metronome which broke!! (how can a mentronome break?). I was working on getting it slower and trying to not rush to easily.
I started out playing the piece as fast as possible, I tend to try being a speed demon with everything, and I actually thought I was playing it slower than it was...
I guess I haven't answered your question: How long I practiced to get it to that speed.... I don't usually need to practice to get to a certain speed. Speed had never been a problem for me in terms of manual dexterity. I type pretty fast (about 120-160 wpm), I try all sorts of fast runs on the violin. Thus, when I work a piece, I'm not concerned about speed, I'm more concerned about how smooth and musical it sounds, and that takes me a while. To get to that speed, it took me about 3 weeks. But I've been practicing (and still am) and working on this piece on my own for about 4 months. I don't get to practice a whole bunch, but I try to touch a few notes almost every day now.
I have a pretty strong musical background with music all my life with the violin and I've had many opportunities to play with well known violinists/musicians. I'm also friends with several music professors who have recently been somewhat supportive of my desire to play piano. Before, they thought it was a passing phase and was worried I would destroy my wife's piano.
So, Tsagari, I read your thread about being an adult piano student. It's a struggle because I think we lack some learning talent that would would have otherwise had as a child. However, I think we have other advantages, such as greater motivation, discipline, and critical thinking. So we have those three things going for us. I have every reason to believe that you and I will continue to improve. I also believe that our main teacher is ourselves, and any teacher we hire would mainly be there to advise, coach, and encourge us. Because I like to be my own teacher, I try to rely on recordings of myself (sound) and now video - which I made my first one (the one you saw). I've watched it a few times and listened to it carefully, and made many mental notes to myself on what I want changed.
Sorry this was so long... we'll talk more!