I think it even applies to "never implement crypto on your own"---are you sure you've taken into account side-channel attacks? Timing attacks? Random number g

I think it even applies to "never implement crypto on your own"---are you sure you've taken into account side-channel attacks? Timing attacks? Random number generation (if it's required)? Cleaning memory after use? That memset() isn't optimized out? There's a lot to get right ... Edit: a few more examples.