Folk that overtake on a dual carriageway then slow down for some fxxxxng reason making you either slow down or have to overtake them
Ah yes. People who want to drive in front of you, slower than you. Truly bizarre behaviour amidst a sea of odd driving habits.
I had one once on a fairly quiet M6. I was sat in the first lane with the cruise control set, minding my own business. An ancient silver BMW overtook me, pulled in, then let off the gas. Whatever, I pulled out, overtook him (still on cruse), pulled back in. Shortly afterwards, he overtakes again. Rinse and repeat. In the end I took out a temporary membership to the Lane Two Owners’ Club and drove from like Lancaster to Keswick with this silly bastard in anticlockwise orbit around me.