When litter is the reality you live in for 90% of your life it's probably seems really normal to litter all the time.
When I was a kid, you wouldn't dare drop litter for fear of a bollocking. I also remember that there were lots of anti-littering campaigns, etc ... maybe what's lacking now, is education and maybe a bollocking
Do you pick up/tidy up the 'trace' when you come across it in the countryside? Equally do you pick up litter when you come across it in your day to day environment?
Yes and yes ... often come back from a ride with someone elses crisp packets and stuff. I also spend quite a bit of time tidying up round the communial bins at the end of the lane after people have just put their bags on the floor rather than in the bins and the local wildlife has done its bit.
Also if you 'leave no trace' in the hills, do you also do it at home? i.e. There isn't a rubbish fairy who makes what you put in a wheelie bin/black bag magically disappear into nothingness once it leaves the curb side.
I try to recycle when possible, however as humans we'll always produce some litter and it must be better for what there is to be dealt with in a controlled way rather than scattering it across the country in hedges, verges, etc.