what you perceived as "stupid" over the other is doing/acting, it may be due to:
1) your ignorance about why the other is doing/acting it
2) the other ignorance about its action.

to resolve #2:
- if the other can learn with open mind/heart, this "stupidity" is over.
- if not, becos due to ego/arrogance/culture, just hope this "S" won't bring harm to anyone

to resolve #1:
- only if you can learn/accept with open mind/heart, then this wrong perception of "S" will be gone.
- else, while you continue to brand the other as "S", the other will brand you as "S" too.

in summary:
- its subject perception, intelligent, personality, cultural