What is the third greatest lie?

For no apparent reason I was thinking the other day of one of my former staff from years gone by. A noted procrastinator, he would always respond to my question of when something would be ready with “Wednesday”. He did this automatically without even bothering to think what the question had been! I recall telling him one day that there were three great lies in the world:-

The cheque’s in the post;

Ready Wednesday;

And ….

I can’t for the life of me recall what the third one was.

Thoughts that spring to mind and / or were suggested by Googling the issue are:-

I’m working late tonight, Darling;

Of course, I love you;

Of course, I’ll respect you in the morning;

..But we can still be friends;

It's not the money, it's the principle of the thing;

I'm from the government, and I am here to help you;

(One for our mechanic) It's supposed to make that noise;

(for the weatherman) Tomorrow will be bright and sunny;

(for Tesco) This fish is fresh;

(and one for Jo) Then take a left. You can't miss it.

But none of those was my original third greatest lie. Any suggestions?