I got "dullmindedness", which maybe isn't a dictionary word stricly speaking, but makes sense gramatically. https://en.m.wiktionary.org/wiki/dull-minded https:

I got "dullmindedness", which maybe isn't a dictionary word stricly speaking, but makes sense gramatically. https://en.m.wiktionary.org/wiki/dull-minded https://en.m.wiktionary.org/wiki/dull-minded