Thank you so much @hglucky13 ! And it s exactly how you describe it... we need to fail in order to learn. We don't learn from successes because we don't know what when right: things are too complex to say "this is right! and this is the right way!". We just learn "this wasn't that bad but this little part from here failed, so I'll shall try something different next time".
At least this was my path as artist and every other profession I heard of =)