[zero-sharp]

So you ignored the context surrounding this piece of advice?

Yea, reinventing the wheel is a great way to learn. You're not going to hear an educator tell you to not reinvent the wheel.

[tehnub]

Yep, not reinventing the wheel is advice you should consider in a business context, not when you’re programming for fun, although I’m sure there are hordes of people giving this advice outside of the business context and perhaps that’s what OP is responding to.

[pona-a]

There are many, many "educators" that will tell you to not dare think about a wheel more than it takes to mount a new one in.