Well in fairness I was trying to alert him/her to the fact their main beam was on! There were no other vehicles in the direct line of my headlamps. And as I saw a van from a sidestreet in the distance turn, so in a moment he would be facing me, I switched them ofk. Also don't forget that the original car driver was in no danger of being dazzled by me - they
weren't looking at my headlamps, they were busy on their phone, texting, chatting, doing their makeup, whatever. Totally unaware of their surrounding. That's the killer - inattentiveness.
I've done it, unaware that I have accidentally knocked my stalk forward, only to notice another driver flashing me; And very glad I was that that happened, off the main beam went, and a friendly wave of thanks/apology. In my defence, there was me thinking jealousy, disrespect for other cultures and beliefs greed and an over-commercialised consumer society-wide attitude is what is wrong with people - perhaps it's people flashing other people informing them that their headlamps are on.