There's an "if" missing from my sentence. My fault. The full thought could be rephrased as, "if the explanation doesn't make any sense, or is too improbable, or too stupid, I dislike the twist regardless of whether I thought of the explanation earlier (and dismissed it as not making any sense, or being too improbable, or being too stupid) or didn't think of it (because it didn't make any sense, or was too improbable, or too stupid)."