Canadian here as well, but I always thought that we had metric system all along!

I just assumed that everyone was using such standards when I was little and then came things like miles, pounds, yards, foot and I was like wtf, it's so complicated.

I know how long a cm is by pinching my index and thumb finger and measuring the distance between the nails. I know roughly how long is a meter based on my height. I know roughly how long is a km based on my running distance.