Bit of an aside here, but that really isn't true. I can't count the number of times I went into an experience and got something completely different out of it than what I went looking for. Martial arts training is only one of these.
But...you only support my statement. If you have an aspect to focus on during practise and during that you find something else that is more
wrong you only shift focus to that aspect. This only shows flexibility and open mind.
When you practise for good fun and by accident you get something out of it, I do not consider that proper training/practise
. You train purposefully to improve something.