Metrication came half way through my education
I'm still only half way through my education and am rapidly running out of time. It doesn't work for me in respect of all metrication. I have got 30cm is a foot and a metre is a yard and a bit, but any other numbers I have to convert into Imperial so they have meaning to me.
Some years ago, when metrication came in, I visited my local timber yard to get some materials for DIY. I asked for some timber - 2 by 2. The chap said, "We don't do that any more. We have gone metric. We call it 50mm by 50mm now". "OK", says I, "How much is it". Without a trace of a smile, he instantly responded, "10p a foot".