Though best known for his fantasy series “The Chronicles of Narnia,” C.S. Lewis was also an accomplished poet and literary scholar. During the Second World War, he hosted a series of radio talks for the BBC, including a sermon aimed especially at young wartime scholars trying to find their paths (from which this quote comes). His words ring just as true now as they did in that fraught time: If we worry too much about the future, we might miss the opportunities waiting for us right here in the present moment.