Jonah resents that God would forgive Nineveh. Laborers in the vineyard resent that last-minute workers would get a full day’s wage for an hour’s work; the first is last and the last is first.
Of course the point Jesus was making is that how hard we work, or how long we have been at it, does not ‘earn’ us the keys to God’s Kingdom. There is NO WAY we ‘earn’ eternal life; that is just not how it works. It is only by God’s grace that we are invited to live with God, in this life and in the next life.