How many times have you lost it?
I cannot remember the amount of times that I have lost my lens cover - I know that one was lost when it bounced into the river when I was taking a shot of the sunset in Trieste. I did have a 'lost and then found' incident when I accidentally dropped the cover into the harbour at Padstow, then a young man when rushing down the steps and retrieve it. I think it has showing off in front of a group of girls but whatever the reason, I was pleased to have the cover back! To resolve my problem with lens covers, I designed a camera strap with a built in cover holder.