Metronome

What is a metronome? I have for a long time underestimated the power of a metronome. Though i knew that it is a very important tool in the development of speed playing i somehow just put that idea aside. I just seem to place it a locker room and is bound for oblivion. But just recently i was dumbfounded when i saw a very small kid play with fingers in lightning speed with all the melody and technicality imbued in it. Then he mentioned about what he did to attain his playing ablity, constant practice with metronome. He just simply said it! I was ashamed of myself, partly because i was ignorant and also because of the fact that this boy is just a fraction of my age but play so well i would think i cant outdo him if we have a playing match.
But i have the fact that i have misguided myself. I will now try to use my metronome as i play or practice. Im sure it will have a good impact on my playing.