“The lecture was interesting, but it was much too long.” “'My sentiments exactly!'” [=I agree with you completely]
A good politician understands public 'sentiment'. [=understands the opinions held by many or most people]
His criticism of the court's decision expresses a 'sentiment' that is shared by many people.
(..) Would you be more convinced if I fell to my knees? Turn me loose, you varmint, and get out of here! Forgive me for startling you with the impetuosity of my sentiments... ...my dear Scarlett. I mean, my dear Mrs. Kennedy. But it cannot have escaped your notice that for some time past... (..)1939 Gone with the Wind