Yeah when we're talking about it here I use Wikipedia or Memory Alpha if there's something I want to check. That said I admittedly know most of TNG pretty thoroughly, but I've been a fan of that one for decades and it's always been a shared interest with various groups of friends. I don't really know TOS anywhere near as well as TNG. I've seen most of the episodes twice (for the first two seasons) or once (for the third season) but there are a few others that I've seen three or four times. The most famous/important episodes are the ones I'm likely to have seen more than twice, talked about, and read internet discussions about so I'll remember alot of those pretty well.
The other TV show I know as well as or better than TNG is classic Simpsons. My familiarity with the James Bond series used to amaze people but I haven't re-watched those in a long time and while I still like a bunch of them they haven't retained my affections the way Star Trek has.