The theme or message of this great song is found in the chorus: "How can you tell me that you're lonely and say that for you the sun don't shine. Let me take you by the hand and lead you thru the streets of London- I'll show you something to make you change your mind"
Almost all religions and philosophies, in one way another teach this- that when we feel down or discouraged about our condition or position- let us remind ourselves that there are always some poor folk who have it much worst.
In everything give thanks for this is the will of God in Christ Jesus concerning you
1 Thessalonians 5:16-18
Let us be thankful!