HIDDEN THOUGHTS

"I am happy for u",does this sentence means what is it suipposed to mean?.Noting the feelings of jealousy screaming out of everyone's heads including my own when one of our friend was within the top 15 eligible for the interview of a "Dream job" company ,why were everyone hiding their resentment into some statement of support.Is it necessary yo camaouflage emotions,so that the other person does not feel hurt?