Someone who is very awkward and clumbsy is all thumbs. Example: Hey! You are pouring my coffee on the table!" Reply: "Oh, I'm so sorry! I have been all thumbs today."

The hand works best when four fingers work together with one thumb; if you had all thumbs (and no fingers) it would be awkward for you to hold things or pick things up. Example: "Oh, darn! I broke a glass. I really am all thumbs today."

Some people are clumbsy with their hands in general: they are all thumbs. But most people just have certain days when they are distracted and so are all thumbs for a period of time. Example: "Ouch! You cut my ear." Reply: "I'm so sorry. I have been all thumbs all day."