To sentimentalise something is to look only at the emotion in it and at the emotion it stirs in us rather than at the reality of it, which we are always tempted not to look at because reality, truth, silence are all what we are not much good at and avoid when we can. To sentimentalise something is to savour rather than to suffer the sadness of it, is to sigh over the prettiness of it rather than to tremble at the beauty of it, which may make fearsome demands of us or pose fearsome threats.