I have let others in front of me and have been allowed in front on numerous occassions..

Even though I am still on my learners (can drive just slack getting proper license lol) I let people in I am in no rush to get places. Dh is a little less patient and thinks why should he. I make him though LOL

I hold doors open for men and women of all ages. If I am holding the door and someone is coming I just hold it.

I find the rudest of all in the shops are the elderly women. They never move out of anyones road. Although iin saying that when I went to the shops this morning I came across 3 lovely older ladies. My darling children were being a bit silly and not watching where they were going and nearly walked into their trollies and they weren't at all rude infact they said.. Oh thats all right dear

So yeh in response to your question I come across common courtesy a decent amount but still think there is room for improvement. I do teach my children basic courtesy