Earlier quoted context omitted.
Not Invented Here syndrome goes away with general experience. It doesn't come back every time you switch to a new language. Just because I've never written Erlang doesn't mean that I will automatically try to write a random-number generator (say) the first time I need one in Erlang. I have enough experience to look for a library function first. Empirically, NIH tends to be more common in single-language developers, n…
I wasn't talking about NIH syndrome, I was talking about "I don't know that a common library exists for this standard use-case so I'm going to write my own one-off because I have a job to do". I mean, you can google for libraries but sometimes you just don't find them and then find out a few weeks later what you should have used.
That's called "laziness", and is even more likely than NIH syndrome to be mitigated by experience. Certainly, having lots of coding time with a single language doesn't make you less lazy, and having lots of experience with different languages doesn't make you lazier.