Bravissimo!
I thought this was an excellent contemplation. You really took one sort of musical thought and mulled it over, exploring its possibilities and giving it many different musical treatments. As any professional musician knows, notes do not make music, it is the treatment of them that makes the notes. Any "incorrect" notes could simply be interpreted as bent or otherwise colorful expression notes that I thought actually added to the piece overall. On the subject of notes, the final ones that you ended on gave me a chill. Truly haunting.
Was this improvised? It has a few of the hallmarks of improvised music but was also very well phrased, unified, and seemed to be structured with regards to form. Most of all, though, it was real, organic, and just downright tasty.
Never stop playing. People around here are harsh on classical and traditional music if it doesn't sound like the soundtrack to every other movie.