A watched pot never boils
This proverb means that time seems to slow down when we wait anxiously for something to happen.
In Ireland when anybody calls to the house, we always offer our guest a cup of tea. If we watch and wait for the kettle to boil, it seems to take a very long time. Whereas, if we are chatting to our guest, the kettle boils before we know it! 
An English novelist Elizabeth Gaskell first used it in ‘Mary Barton’ (1848), giving the exact wording of the current version.
“my master told me to see you to bed, and I mun. What’s the use of watching? A watched pot never boils, and I see you are after watching that weathercock. Why now, I try never to look at it, else I could do nought else. My heart many a time goes sick when the wind rises, but I turn away and work away, and try never to think on the wind, but on what I ha’ getten to do.”
Example Sentence:-
Tony said that he could not wait any longer for his birthday party. I told Tony not to think about it because a watched pot never boils.
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