The Boolean satisfiability problem (SAT) was proven in 1971 to be NP-complete — suffice it to say, no fast solution exists. That being over 40 years ago, it is OLDWorthy.
But with today’s fast computers, super efficient algorithms, and artificial intelligence research, SAT solving has benefitted greatly in the last couple of decades. Satisfiability (SAT) is again NEWWorthy. Just understand that it also increases our dependence on computers for answers.