Why do people flash their high beams and drive like idiots around me?

I drive a boring base 2015 Honda Civic and commute for a couple hours a day and just tonight at least four cars flashed their high beams at me when there wasn't a cop or had my high beams on. Two different cars actually put them on and stayed behind me in the right lane when they easily could have passed. I just put on cruise control and try to relax the entire trip because it's so stressful. Should I just avoid the highways altogether even if it takes a little longer or am I being paranoid?

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