Do I need to understand the nuances of how I got saved?

Well, it depends on what you mean by nuances. If you mean the distinction between being judged according to works and being judged on the basis of works, that's a huge and significant difference.

That's because the Bible is so clear—and our own consciences bear witness—that if our acceptance with God is grounded finally in our performances of the law, in doing good deeds, then I'm not going to have any security here and I'm not going to be accepted with God in the end. God demands a perfect righteousness, which is what Christ provides for us in his own obedience; and he demands that we be forgiven for our sins, which is what Jesus' blood provides for us on the cross.

Yet the Bible also talks about judgment according to works, which is why I labor to distinguish between the ground of my acceptance with God (which is the blood and righteousness of Jesus Christ, perfect and unchanging) and the evidence that I'm trusting him (which is my growth in grace and the good works that God will point to at the last day as the evidence that I was born again). And that evidence doesn't have to be perfect. Clearly it is not perfect. Paul said, "I press on, not having been perfected, but I press on to make it my own" (Philippians 3:12).

So if those are the nuances you're talking about—the difference between the ground and the evidence of our acceptance with God—that's a very big and important difference.