Accidental English accent...?

I realise this probably sounds incredibly stupid, but sometimes after I watch an English movie or television show, I pick up an English accent that I actually cannot get rid of for at least a few hours. It usually is some vague London-ish accent, regardless of whatever accent I'm actually watching, although sometimes it turns a bit Es-ish. I'm not looking for a way to make this stop, I'm just curious as to whether it happens to anyone else...