What I wouldn't give to be 15 years younger and know what I know today.
Intelligence and Wisdom are really about our ability to know things. Do you know what to do? Do you know what that is? Do we know a lot of things, can we figure things out.
What they don't represent is our experiences of having been there - what have we actually seen and done.
The first time we experience something in life is almost universally the most intense experience we will have with that thing. It is why youth and our teenage years are filled with so much angst. Our first loves and breakups are chemically more intense inside our brains then those of later years. (Of course there's the small matter of super-powerful hormones flooding your system also, but in general novel experiences cause the most change in our brain).
This is also evidenced in athletes, competitive gamers, soldiers, programmers, functionally all areas of life.
The first time you run a course, it will not be your best time, because you're forced to process a lot of extra information. In a fighting game, there is so much motion and activity on the screen, often you can't even tell what's happening at first, but eventually all that fades away, so that you only receive the relevant information. Then when you are playing time seems to slow down, and you wonder how anyone could miss the information that you see.
And so it is in RPGs. The increased experience doesn't mean that you're suddenly endowed with greater ability (well, mostly not - there's a bit of that in superhero edition). The reason your saves improve is that the tenth time you jerk back from a poison needle trap, you were probably expecting it more than a little bit. The fiftieth orc is a lot less likely to surprise you then the fifth orc, simulated by the larger number of hit points. Your familiarity with forcing arcane formulate into your brain means that it no longer takes the same effort it once did.
To understand what is going on the first time would mean that things would not be as they are. That is often what we wish we could do, go back with the experience we have and do a different thing. It is one of the great things about Dungeons & Dragons (that your experience with the game continues to improve, so that when you're starting out with a new character, you will play better then you did the last time). And there is something in that, for we cannot go back and relive our lives. But we can continue forward with the knowledge that we have, and maybe keep a few more PC's alive then before.
Oh, and use some of that experience to be a better person, of course. :-)