My boss is going to hand me something (to test the solubility of) that is actually soluble at the lowest concentration I am supposed to test and I am going to faint dead away. :p Or stare at the clear solution for hours trying to decide if it really is clear, or it's my imagination. Which reminds me of a Bill Cosby skit about playing football for Temple. It goes something like "I looked up to see... a hole! I had never seen a hole before, playing for Temple. I said "God! A hole!" The coach was waving his arms and saying GO!GO!GO. I was like 'Wait, wait, it could be a mirage!'"
Still tired. Wonder if it's a touch of anemia? Could be. I shall endeavor to remember to take some iron supplements.