In 1979 I don't believe the FO were issuing warnings. I was in Peru and travelled to Lake Titicaca by train where I took the overnight steamer (built in Hull in 1928!) across the Lake. When we arrived in Bolivia we were told the trains were on strike and to take the bus to La Paz.
Half way to La Paz someone on the bus had a radio and said "I think there's been a revolution". El Alto (the town above La Paz) was heaving but as we descended into La Paz there were no people around. The bus dumped us by the station and left. At 16000 ft with a back pack walking isn't easy but we found our way around the road blocks through back streets to our hotel.
The next few days were boring while the two sides argued and one night took pot shots at one another outside the hotel (we spent the night in the bath room - at least one more layer of breeze block to protect us). Eventually a Peruvian bus company decided to take their bus out and sold us tickets. At the 2nd try (the road was blocked the first day) we got back to Peru. I believe that the following day all the foreigners were taken to the airport and shipped out by the military.
Even today I'm not sure I would have even seen the FO warning if it had been present - who foretold Tunisia or Egypt? Did I try and get the bus fare back from the FO? No. I simply took the view I had got into this; I needed to get myself out.
That experience taught me a few things but it doesn't stop me travelling and, even now, I rarely look at the FO site except for amusement. I'm the only person who can keep me safe; I have to take responsibility.
Oh by the by that Peru/Bolivia trip was our honeymoon and she hasn't divorced me yet!