Solomon, inspired by God, wrote these words in the book of Ecclesiastes:
To everything there is a season, A time for every purpose under heaven:
A time to be born, And a time to die;
A time to plant, And a time to pluck what is planted;
A time to kill, And a time to heal;
A time to break down, And a time to build up;
A time to weep, And a time to laugh;
A time to mourn, And a time to dance;...(Ecc.3:1-4)
Nate is apparently a very mature baby, because as you can see in this picture, he seems to already understand this.
Perhaps in his case it could be phrased: A time to be serious, And a time to be silly.
Oh, and by the way - his shirt reminds me of that Pirate movie. You know the one, right? It was rated ARGH!