Nearly all assumption fits into two categories. We either assume that other people do things the same way we do or we assume other people will do things differently. Both make the bigger assumption about ourselves.
If we do things how everyone does them, then we are just like everyone else.
If we think others do things worse than we do them, we think of ourselves as superior. Pride goeth before the fall.
If we think others will always have better results than we do, we’ve made our own glass ceiling.
It’s generally best not to assume anything at all.