My 66 plate 1.5 dci had a weird clutch fault that started on the 1st long journey I did, it simply slipped on uphills in the higher gears. Now I too have been driving for almost 50 years and do not mistreat clutches. Drove it carefully and booked in at the dealership.
Problem was I couldn't replicate it on the short test run at the garage with the chief mech sat with me, only later found it only slipped when really warm. Over the last 12k miles it's done it 3 times more, each time exactly as above, you could smell burning clutch on one occasion.
However because I normally drive for economy, (I think this is why it's survived so far), and don't do long runs and am mostly just 1 or 2 up, I've not dealt with it further and to be honest not noticed it over the last 6 months.
Big difference in my case is the cars on lease and as I don't want the inconvenience I not pushed it further, just ensured the issue was logged when it first occurred and then at each service.
I think mine would have gone just as early had I driven it harder.