Without knowing any details I can only speculate but 10 years is a lot of time to refine your experience and expertise in a field. Do you remember what game it was and why it didn’t amount to anything?
Currently looking for a new 4x game that will scratch my itch. Been going through tons but they all seem like watered down versions that “simplify” the process. Last game I played was SpaceEmpires (4&5), completely addicting but after over a decade of bugged games I’ve just completely given up on it. Definitely got my playtime out of it though, great game regardless.