I started off, like my esteemed friend Whirlygig, by not writing anything down. You gradually develop a better memory. If there's too much information, you repeat back what you remember, and ask them to say again the bit you forgot. But I rarely write anything down these days, even when I'm flying f/w aircraft.
However, a very high hours pilot pointed out to me that someday I might get a long clearance and I'd have to write it down! How? Become ambidextrous on the cyclic, he said. As a helicopter pilot, this is what you need to do; don't mess about. Well, as an instructor I had to do that anyway, so now if necessary I switch the cyclic to my left hand and write things down.
This is not really a digression. As a pilot, you're ALWAYS learning. Just because you got a PPL and can fly from A to B and manage on the radio, don't think that's enough...it's nothing; it merely means you know enough to do some of the learning on your own. And the little bit of RT you had to do for the Skills Test? Think of all the things you didn't have to do, like a Mayday call, and - depending where you fly from - possibly not flying through a MATZ or controlled airspace or any of the myriad of things you are now officially QUALIFIED to do. I did my PPL before they had an RT test. There was loads of stuff I thought I knew, but had never practised. Sure, I sounded OK on the radio. But there's more to it than that, and way, way, way more to flying than what you know now....or what I know for that matter.
Oh, and if you ever want a demo of what helicopters do in the event of engine failure, come and fly with me and I'll show you!
Whirlygig, learn to use that stick with your left hand! 