Manners and shit

If you were brought up with good manners and such then the gentlemen amongst you will, I'm sure, hold the door for ladies, pull out their chair for them and walk on the street side when walking together. This latter custom began way before the invention of the car and so is nothing to do with protecting your date from careless motorists

It almost certainly dates from way back when cities did not have sanitary sewer systems or inside toilets. Citizens would use chamber pots at night and in the morning they, or their servants, would often avoid a trek down to the cess pit (in many houses this was basically just the basement) and fling the contents of the chamber pot into the street from an upstairs window. Streets were pretty much open sewers then anyway but this certainly didn't help. The custom evolved that gentlemen, when escorting ladies, would position themselves closest to the street nearer to where the sewage would hit the ground thus preventing their date from being splashed, or, worse, hit. Of course the downside was that you would end up covered in excrement yourself.....

Some people long for the simpler times of the past. I like the twenty-first century just fine.