New, popular frameworks don’t solve all your problems as they promise.
There isn’t a best coding practice that all developers are willing to follow.
A clean and beautiful UI on the client side will be more important to users than a high-performance, highly available server.
Even if your code passes all the unit tests, it doesn’t mean it’s problem-free.
If your program crashes “accidentally”, it’s often not an accident and will continue to happen. Don’t lie to yourself.
Even if your code is well-written, it doesn’t mean your product will be successful. And even if your code is poorly written, your product can be successful.
Your “novel” idea is often an option that others have tried many times and finally given up on.
Even if your inherited code looks like crap, don’t refactor it, or you’ll probably screw up the project.
Most of your needs have been solved by some open source library or packages.
Technology doesn’t solve anything.
There are no “learn JavaScript in two weeks” or “master C++ in one-month” tutorials.