'Easter' is a movable event, calculated by the relative positions of sun and moon, an impossible way of fixing year by year the anniversary of a historical event, but a very natural and indeed inevitable way of calculating a solar festival. These changing dates do not point to the history of a man, but to the hero of a solar myth.
I don't know about happy endings, because I don't think, eventually, anything is happy. You feel a bout of happiness with good news. Five minutes later, there could be a traffic jam or a phone call from an irritating relative or a weird thought, or it could be a tweet that annoys you, and your emotion will flip immediately.
Sometimes the routes leading to feelings of anger are so convoluted and circuitous that it takes enormous skill to discern their original source, or fountainhead. But regardless of the reason for or the source of the anger or the relative ease or complexity in perceiving either the anger or its source - everybody, but everybody, gets angry.