>>283600911
"Modern knowledge" is basically short for when writer makes everyone from the native land a complete moron to hype up the MC when he creates totally awesome tools that nobody has ever heard about like pic related

Ideally, a MC should only have knowledge of things his background would justify knowing. Eg a doctor would know his way around medicine better than natives who use magic instead. At the same time, MC should also fields where he has no knowledge about that the natives would even consider common sense.