I find that lamentation a bit funny, because the list in practice is never really complete. For instance, you forgot the mighty Prolog. Surely, tcl belongs on there too.
Also SNOBOL/Icon.
The more of them you explore, the more insight you get. The list does not have to be complete. It just needs to list some languages, that are truly different in how they work and what the ideas behind them are.
I blame the unknown unknowns. I don’t haven’t learned Prolog yet. Alas, enlightenment still eludes me.
(Agreed that TCL is pretty cool)
If I have to describe the feeling is that you'll realize that computation is symbolic manipulation (yes, it is obvious, but quite difficult to be fluent in it). With C and the likes you're too close to the machinery to easily grasp symbolic manipulation. But with other paradigms like lisp, prolog, oop with smalltalk,... you start learning how to design solutions in terms of symbols and their manipulations instead of values and concrete actions.
Once you start doing that, you move a ladder up in problem solving, where you solve class of problems instead of specific instances.