With accent marks:
Сы́тый голо́дного не разуме́ет.
A well-fed man does not understand a starving one.
A well-fed, prosperous person does not want (and often is not able) to understand what it is like to be hungry.
The old Russian word "разуметь" in this case means "understand".
Other Russian proverbs
Crowded, but not aggrieved.
Оne can not see the wood for the trees.
If I knew where I would fall, I would lay some straw there.
A bad example is contagious.
The beauty of a debt is its payment
Don't go to the woods if afraid of wolves.
Poor people are inventive.
Don’t wave your fists after the fight.