For what it's worth, events conspired against me and I didn't quite make it...
Was accepted as a T2B (Improver Technician) for the GPO at Whitehaven exchange in 1980 after a year 'out of my time' as an electrician (British Steel) - where duties included maintaining an ancient Strowger PAX and system.
Passed GPO medical and was told to expect a starting date. Nothing forthcoming, and, after enquring, was told that wouldn't be required! Pending privatisation was cited...
Undeterred, got on a BT-run telecomms, electronics and electrical principles TEC III / IV course at Bispham Technical College where every other student was a (by now) BT employee. Some big cheese from BT came on a visit to see how his chaps were getting on and to take a photo for some 'in-house' magazine or other, and was greatly embarrassed to find me, an interloper, on their course! I was aked to stand aside for the photo. I took the opportunity to point out how shabbily I'd been treated in the past by a so-called 'prestige' company and was promised an explanation: I'm still waiting...
Passed my exams. got a start as a trainee Transmitter Engineer with the BBC and never looked back. Much in common with GPO re: organisation, hierarchy, training, etc...
And guess what? I still get to do telephones to this day!