Because lunch simply doesn't exist in some languages, here in Poland we have breakfast, dinner and supper, lunch came as an western import after communism fell, anyway why name your meals?
Today I learned
ahhh, that makes a lot of sense. (learning Polish), for some reason i thought obiad was just lunch and kolacja was dinner but this makes more sense
This has a lot to do with how English is taught in Russia. When I was a school kid (long time ago) we learned that there's breakfast, dinner and supper, dinner being the midday meal. It was not until much later that I also learned words like lunch, brunch etc.
When I was a school kid (long time ago) we learned that there's breakfast, dinner and supper, dinner being the midday meal.
… which isn't wrong, just incomplete.
Note that "lunch" and "dinner" both can refer to the same meal, a midday meal, in English:
Yeah the definitions for lunch, supper, dinner, and tea have been rather unstable in contemporary English; a real dog’s breakfast.
The main meal being the evening meal is largely an artefact of the Industrial Revolution, when large parts of the population spent most of the day at a workplace away from home. In agrarian societies, the main meal, i.e. dinner, being in the middle of the day was more common, and the smaller evening meal was referred to as supper.