Just had conversation with husband. Went like this:
It's ok to take my hair straighteners in my hand luggage on holiday, isn't it?
Well yes, you took them last time, didn't you?
Um, I have worn my hair curly for years and years..I've never taken them on holiday with me..
Are you sure, I'm sure you took them with you?
Um, I haven't even used them for so many years..my hair has been curly. Did you not notice?
.................
Well there you go, that's how much he notices. I would notice if it was him! 
(new haircut means I've been straightening my hair for about a week now).