Brought up in the Imperial system..... Hmm. Were you?
As long ago as 1838 a Royal Commission for the Restoration of the Standards of Weight and Measure was appointed and in it's report referred to the advantages of establishing decimal currency in the UK, going on to say that this was required before reform of weights and measures could be undertaken.
Joseph Whitworth (he of screw thread fame) proposed a decimal measure of length for mechanical engineering in 1857, so the thousandth of an inch (or ‘thou’) was added to engineers’ vocabulary. In the same year a British branch of the International Association for Obtaining a Uniform Decimal System of Measures, Weights and Coins was formed
in 1862 a Parliamentary Select Committee unanimously recommended that the use of the metric system should be made legal but that “no compulsory measures should be resorted to until they are sanctioned by the general conviction of the public.”. This lead to the 1864 Weights and Measures (Metric System) Act which permitted the use of metric measures for ‘contracts and dealings’.
The United Kingdom became a signatory of The Metre Convention and joined the General Conference on Weights and Measures (CGPM) in 1884.
Even in 1904 at the first British Olympics all the track events were measured - in metres
I was educated in the sixties in both systems and can switch fairly readily between them - measurements like furlongs, chains and bushels are illogical and just leave me shaking my head, Who in God's green earth would want to return to that nonesense?
So metric has been with us, legally,. for a very long time indeed, even our weights and measures are actually tied back in law to a series of metric measures made by Johnson Matthey in 1889. BTW Britain received standard metre and standard kilogram no. 18.