No other stroke comes close to conserving your energy while getting more distance per stroke. In this stroke you will pull and kick at the same time then glide for as long as you can maintain your level body position. With your body floating on your back you get more time to freely breathe and recover if you’ve become exhausted swimming another stroke.
It pays to know how to do a good back glide and float. It also helps to know how to kick breaststroke so you can do it on your back. Ideally if you know how to scull your hands to maintain your floating you can see the three separate subroutines in your kick sequence.
In psychology this is called paired-associate conditioning. You condition what you see with what you feel doing your kick to teach yourself and make more resistant to forgetting as you are now getting a visual image in your brain. Even if you rollover on your stomach you can make a mental pattern of how your kick works.
Watch the video to get a better idea why learning this stroke is far more valuable than sidestroke which I no longer teach.