In a recent class, my Japanese teacher taught me the use of しも as something akin to a formal version of でも as in the following sentences:
I was told the above sentences have the same meaning, varying only with formality.
Now, when she wanted me to practice using しも, she gave an example that uses it in a completely different way from what she explained. She gave the following sentence:
I understand the meaning. But I don't particularly understand what the use of しも is in this sentence. For me, the meaning stays the same whether or not しも is there (though this might only be because I don't really get it). My teacher explained it simply as an emphasis and told me I should try making sentences using しも like this on my own. But I don't see how I can try making up sentences when I don't really understand what it's for. No matter how much I search for しも, there is no explanation for it used as an "emphasis".
I tried searching about 必ずしも and I found results saying it means "not always (necessarily)" and that makes sense. Does this mean then that しも acts as some sort of negation? If so, is it just attached to adverbs? How is it formed/used? If not, what is it then?