Walk and chew gum (at the same time) humorous
Often used in the negative to convey ineptitude.
If you "walk and chew gum at the same", you do two or more trivial tasks at the same time.
"Is she walking and chewing gum at the same time?" - "Yes, she is typing a document and answering a call".
I couldn't walk and chew gum at the same time because of distraction.
There is no efficiency at all when you walk and chew gum.
The verbs "walk" and "chew" should be conjugated according to their tense.
If you fall for someone's trick the first time then they are at fault.
Are you going to mess with me again? Fool me once, shame on you; fool me twice, shame on me.