an egghead: a very intelligent person.
"Jake didn't make very good grades in school, but his sister was a real egghead."go with the flow: take things as they come.
"There's no need to worry. Everything will be OK if you just go with the flow."get going: leave.
"Look at the time! I'd better get going!"get a kick out of something: find something amusing.(=enjoy)
"I really get a kick out of listening to children talk. They say some very funny things."get on one's nerves: irritate someone; make someone upset.
"I know you like that song, but it's getting on my nerves. Can you play something else?"get a move on: hurry
"If you don't want to be late, you'd better get a move on."get one's wires crossed: be confused or mistaken about something.
A: "Bill said there was a meeting this morning. Don't we have one?"grab a bite: get something to eat.
B: "No. The meeting's tomorrow. I guess Bill got his wires crossed."
"I'm really hungry. Would you like to grab a bite with me?