How to remember the structures of purines and pyrimidines?

[Frigus]

I have drawn structure of purines and pyrimidines literally 14 times but still I am not able to recall the structures of these tiny monsters after few days of learning them.
Can you please tell me how you remembered these structures.
Thanks😃.

 

[shjacks45]

They come in pairs in DNA. Draw them as hydrogen bonded pairs GC and AT (AU). Next up Inosine, Hypoxanthine, Uric Acid ...

 

[jim mcnamara]

Sometimes 'bond line' drawings help, but my basic go to was the stick diagram:


This was 60 years ago, so no youtube...