A business man got on an elevator.
When he entered, there was a blonde already inside who greeted him with a bright smile, T-G-I-F. He smiled at her and replied, S-H-I-T.
She looked puzzled and repeated, T-G-I-F, more slowly.
He again answered, S-H-I-T.
The blonde was trying to keep it friendly, so she smiled her biggest smile, and said as sweetly as possibly, T-G-I-F.
The man smiled back to her and once again, S-H-I-T.
The exasperated blonde finally decided to explain.
T-G-I-F means 'Thank God, It's Friday. 'Get it, duuhhh?" The man answered, S-H-I-T means 'Sorry, Honey, It's Thursday' -- duuhhh.