I don't think you can. I had something like 117 complete playthroughs in Baldur's Gate, with about half after TotSC. I had 90 some odd playthroughs of Baldur's Gate 2, including ToB. I can't recall the exact numbers for the IWD series, but there were quite a few, one recently for IWD.
I then played NWN for 5 years, but, in NWN, I spent the better part of that either in the Tool Set, or in modules created by other players. However, it wasn't because it "felt" like Baldur's Gate or IWD. It had it's own identity, and the modules were all unique unto themselves. However, just as with a first love, you're never going to find that intensity again. I was in my 30s when BG released, and was happily playing things like Doom and Quake as Shareware when my GF at the time brought BG home. I never looked back.
With all that, when I recently tried to play it again, it had lost it's "luster". It wasn't as shiny as I remembered it being. When I look back at it, I still get those tingly feelings. I've never gotten those again from a game, in the same way. I have loved other games, in the genre and out, but they've never had quite that pull on me that I got the very first time the music for the Friendly Arm Inn had when I arrived on the map for the first time. Not even with BG 2, which seems to be the more popular game. It's that "first time" thing, and there's a reason it's the granddaddy of them all in so far as cRPGs are concerned.
I've played 100s of other games, some good, some bad, some just ok. But none of them, no matter how much I loved them, gave me that "first time feel" like BG did. They can't, because they'll never be "First". I didn't come here looking for that particular feel. I came hoping that this game will be another one that has me looking at the clock realizing that I haven't been to bed, and it's almost time to get up. I just had that last night, after finally getting my computer back up, and reinstalling Horizon Zero Dawn. I looked over at the clock, and it was 4 AM. That's what I'm looking for when this game releases. I'm not looking for it to fulfill an itch to return to the original, because I know it can't. I am looking for it to take me by the hand, and tell me a story that makes me realize that I've been "in the world" for far too long, and if it can do that, it's going to be successful, for what I both want, and expect, from a new game in the FR.