Щ3
ЗА ЧУЖОЙ ЩЕКОЙ ЗУБ НЕ БОЛИТ (saying) one does not or cannot feel the pain of another or truly empathize with his grief, misfortune
etc: - your neighbor' toothache can't (won't) hurt youwhen your tooth doesn't ache, you can't sympathize with another' aching toothwe can always bear our neighbors' misfortunesyour neighbor' burden is always light.