All the things that happen to us produce an emotional response. Thankfully, emotions move through us if they are allowed to be expressed. If emotions cannot be expressed they are stored in the psyche. The long term implications of these simple and obvious facts are critical to human stability.
To elaborate, if we lose someone we love then we become sad, if we are allowed to mourn, then the sadness eventually passes. If someone hurts us, we become angry, and if we are allowed to protest against the violation (hopefully appropriately and in a way that our protest is heard and respected) then the anger dissipates. The exact type and intensity of emotional response to given events will vary depending on different personalities and their psychological history, but emotional responses cannot be avoided.
If (for whatever reason) the normal function of emotional response and subsequent expression is inhibited, unprocessed emotions will lay themselves down in the psychic bedrock in layers upon layers upon layers, all filled with potential energy. And one day, when it gets hot enough, they will blow through a crack into consciousness. This eruption almost always wreaks havoc and is usually a great surprise to everyone.
So, it follows that we should think twice before we tell ourselves and others (especially our children) that we must “get over it”; that things are “not so bad”; that we must “stop crying”; that we must put “a lid on it”; that we should stop “throwing a tantrum”. We need to stop preventing emotional expression either through unspoken disapproval, or explicit prohibition. Little meltdowns every now and then are preferable to a major eruption that destroys everything in its path. And interestingly, the more we are allowed to have our true emotions and are supported through their expression early on, the better we become at managing them constructively later in life.