Here’s a good Churchill quote to start this answer, courtesy of Rad Reffer Jenna and The Book of Unusual Quotations (p. 232)

I am reminded of the professor who, in his declining hours, was asked by his devoted pupils for his final counsel. He replied, "Verify your quotations."?

First quotation: "If you're not a liberal when you're 25, you have no heart. If you're not a conservative by the time you're 35, you have no brain."

Besides the Churchill Centre, www.winstonchurchill.org, saying that this quote is misattributed to Churchill, we also found other references saying that it was not Churchill who said this. (McManus, Terry. "A Democratic Medium Plays Big 2000 Role …" Advertising Age 11 October 1999) As well we checked all the sources listed below. From all this information the most likely conclusion is that the quotation can't be attributed to Churchill.

Second Quotation: "No, of course not. Why should I be? They are Englishmen, after all!"

We could not attribute this quotation to Churchill. The sources checked are below.

Another time-consuming option (which we didn’t do) would be go through Winston Churchill’s complete speeches and papers, see “Additional Sources" below.

You can find out if your local library has these sources at RedLightGreen

Online Sources

• Bartlett's Familiar Quotations
• Oxford Reference Online Quotations
• LexisNexis Major Newspapers
• ProQuest Historical Newspapers
• Times of London Digital Archive

Print Sources

• The Times Book of Quotations (2000)
• Oxford Dictionary of Modern Quotations (2002)
• Cassell Dictionary of Contemporary Quotations (1996)
• Man and Affairs: a Modern Miscellany (1967)
• Familiar Quotations (1980)
• Everyman's Dictionary of Quotations and Proverbs (1951)
• Webster's New World Dictionary of Quotable Definitions (1988)
• Dictionary of Literary Quotations (1990)
• Dictionary of Quotations (1968)
• Macmillan Dictionary of Quotations (1989)
• Contemporary Quotations (1964)
• Respectfully Quoted: a Dictionary of Quotations Requested from the
• Congressional Research Service. US GPO 1989
• The Oxford Dictionary of Political Quotations (1996)
• The Book of Unusual Quotations (1957)

Churchill Specific Sources

• Churchill, Winston, Sir, 1874-1965 and Halle, Kay comp. Irrepressible Churchill; a treasury of Winston Churchill's wit. Cleveland, World Pub. Co. 1985.
• Churchill, Winston, Sir, 1874-1965 .The sayings of Winston Churchill / edited by J.L. Lane ; with an introduction by Robert Blake. London : Duckworth, 1992.

Additional Sources

• Churchill, Winston, Sir, 1874-1965. The collected works of Sir Winston Churchill. London: Library of Imperial History, 1973-1976.
• Churchill, Winston, Sir, 1874-1965. Winston S. Churchill: his complete speeches, 1897-1963. Edited by Robert Rhodes James. New York: Chelsea House Publishers, 1974.