I made no comment on Mrs. Thatcher, I'm simply pointing out that longevity doesn't necessarily mean full popularity. Michael Foot in 1983 was nigh-on unelectable, so she won that election almost by default.
Well he's certainly close to the top of the list of PMs in the last 100 years. I think the actual shortest-serving is Bonar Law, then Douglas-Home, then Eden. Either way, the point stands, because Eden was hugely popular but lasted only just over 18 months.
Aged 14 sat in the PMs chair. Got a 'Aye laddy, now feck off out of there' from some po-faced Scot front-of-house but, for 30 secs or so, I held the power in this country. No red button to push though.