Jukka Aho wrote:...Despite using the inessive case in this seemingly illogical way, native speakers, of course, don’t really think in terms of literally wearing these things
in their body parts; rather, it is just an idiomatic way of expressing the idea of wearing something on some body part in Finnish. Idioms often aren’t too logical, or the original logic behind them might have been lost in the mists of history.
To tell you the truth, expressions that use the inessive case in that particular way don’t really make too much
logical or
analytical sense even to the natives.
Jalat kengissä, for instance, is a much more logical expression than
kengät jalassa – which is actually a weird thing to say, come to think of it – but yet the latter is the idiomatic way of expressing the idea of wearing shoes in Finnish. But native speakers have the luxury of hardly ever needing to do this kind of conscious analysis of the common expressions in their own language since it all comes naturally to them and doesn’t need to be memorized or questioned any longer... not to mention explained in a logical way... until a non-native speaker points out a discrepancy and demands an explanation...

And would I be just such a demanding non-native speaker??...

But, of course, feeling the need to "defend" the logic of Finnish to a personally rational speaker of, perhaps, the most irrational of the European languages seems a bit pointless...
Us (we--for the pedantic), native English speakers, learn early on to take irrationality in stride, and some of us even seem, somehow, to view this as a "linguisitic strength"...don't ask me how...

Of course, once a lingusitic convention is established, consistency would then seem to be more important or significant... So far in my quest to learn Finnish I do see a lot of consistency and rationality...
Here's that famous example of English language rationality..mentioned in another post here recently ..."ghoti"...as in "tunaghoti sandwich"...
English, of course, "suffers" because for so long it was a peasant language...adding bits and pieces from other more sophisticated languages, such as French and Latin to an essentially rational Germanic substratum...(French, of course, is a "peasant" language compared to Latin...but that's another discussion) ...and speaking of Latin...now there is beauty and elegance.... Consider this...it ties in with some of the posts above..."Cogito ergo sum"...Three words...two verbs and a connective... Look what it takes in English..."I think therefore I am"....and Finnish,
Ajattelen, siis olen (olemassa)...
Languages...lot's of fun...
