Same here (as a kid growing up in the 80s) - it was always a drink for when you were ill. Lucozade also had a reputation as being even more sugary than other fizzy drinks. I'm sure it was even marketed back then as an 'energy' drink.
I see that nowdays even the sugar-free lucozade is advertised as an energy drink, I'm not sure quite how that works, though!
These days, Lucozade Sport (in multiple flavours) has taken over, but being "isotonic", presumably has various salts.