Assess the level of the emotion sadness in the tweet provided. Use the following categories: 0: no sadness can be inferred, 1: low amount of sadness can be inferred, 2: moderate amount of sadness can be inferred, 3: high amount of sadness can be inferred.
Tweet: Why is it that we rejoice at a birth and grieve at a funeral? It is because we are not the person involved. ― Mark Twain
0: no sadness can be inferred