"The magical number" is a psychology article about the number of things one can keep in their mind at the same time.
"Cargo cult" is a type of cult which appeared in the Melanesia, in which the natives would build their copy of an airplane (no motor, 'cause they didn't have the knowledge to build one -- or even knew what went inside the airplane) in the hopes they would get the same results as a real airplane.
Simple rule: Is the code yours or from your team? Good, you can make any changes you want. Does it come from outside? DON'T. TOUCH. IT.
Most of the times I saw design patterns being applied, they were applied as a way to find a solution, so you end up twisting a solution -- and, sometimes, the problem it self -- to fit the pattern.
A lot of times I heard "We should use the right tool for the job!" Most of those times it was just a way to push an agenda.
Maybe you're in a project that needs to process some text. Maybe you're tempted to say "Let's use Perl" 'cause you know that Perl is very strong in processing text.
But that may still be not the right tool.
You may be tempted to use a list (or tuple, if your language allows) to keep your data if it has, say, only 2 fields. Don't.
Although that sounds weird, it's better to not add any error handling than silently capturing errors and doing nothing.
Memory is just a sequence of bytes; bytes are just numbers from 0 to 255; what those numbers mean is described on the language type system.
If you know an error can occur, then you should handle it properly, instead of ignoring it.