2 pair glasses 2 of something shoes 2 pair of socks

Is two of something always a “pair” of something?  Take a look-which one of these things doesn’t look like the others.  Today’s photo inspiration was 2 of something-you would think that you could then just think of things in pairs.  Right?  I wear glasses and like pliers, trousers, scissors and jeans there is only one but we call it a pair-a pair of glasses.   A pair of shoes makes perfect sense-and socks, unless they have been in the washer/dryer are always in pairs-meaning there are two of them.  In fact, we have even made the word “pair” a verb, as in “pairing” up socks.  Yogi Berra,  famous for fracturing the English language,  once directed his baseball team to “Pair up in threes.”  You can see why Yogi was a little confused.