a couple of years ago i went to Amsterdam for work meetings, i had just come back from Scotland the day before flying over, only going for 3 days so just had a carry on bag with me.
I put a small daypack in my carry on bigger bag.
When i got to the hotel and unpacked and put stuff in the smaller back to take to the meetings, i noticed there was something in front pocket of the small bag, instantly knew it was my folding knofe, which had been with me in Scotland.
it was a UK legal carry one like this https://pbs.twimg.com/media/DcM_v9YXkAAJvpa?format=jpg&name=900×900
Been right through Heathrow security with that in the bag, would have been “interesting” if they had been awake in security.