Few years back now when I was 14-17 I used to come in/out the UK a few times a year from Europe alone.

I don't remember anyone ever asking anything more than "Where have you flown in from?". Within Europe (mainly France/Spain) I think you were lucky if anyone ever bothered to open your passport to look at it. Same situation these days if going to France on the boat from Dover. The French really couldn't be less interested in whose coming in.