"find the way in all things, to master one thing is to master all" this saying has been the driving force behind my training and for the life of me I can't find the exact text that I got it from.
I have to admit my teacher put it a little differently "It's all the same....stuff".
To those who are interested in learning other arts I would say to become really good at one thing (10,000 hours makes an expert) it can be anything at all. Then rather then focusing on the differences between what you know and what you are learning focus on the the similarities.
There are base principles for movement that exist in all movement practices (eg dance). There are base principles of strategy that exits in all strategic practices (eg games). There are base principles for problem solving that exist in all problem solving practices (eg life).
Using your own strengths and past experiences as a platform is the key to mastering new skills. A teacher is only the guide.
I feel like we can be too critical of styles within the martial arts world and we all have our own version of the 'situation you use your skills' and if on a surface level that martial art doesn't seem effective to that situation then it is deemed ineffective. This is a very presumptuous way of thinking and a little closed minded.
Martial arts are developed in necessity and continue to change with the people who practice them. Training is driven by purpose knowing why someone trains is the key to understanding what it is they do.
So before you judge a style you have seen on youtube shake hands with the people who practice that style and see where it leads, you will be pleasantly surprised.