All things were created by him and for him.
Someone who makes something has a special knowledge about it. You could argue that there's no one who knows it better.
Who knows the plays of Shakespeare better than Shakespeare? Would even an expert in Shakespeare know them better than Shakespeare himself?
I find myself underestimating statements that have the word "all" in them. I forget how audacious that claim is. To say that all things were created by Christ is to say that you could pick any single thing, and it would be true to say, "This thing was made by Christ."
That is why, even though this verse is rather short, it is too much to think about. I can't think about all created things. As if that weren't enough, it not only claims that all things were created by Christ, but also that they were created for Christ.
That means we can also pick any single thing and say, "This thing was made for Christ." This is equally mind bending. Who could even attempt a list of every thing? Who can hold that list in their mind an apply even one of these statements to it?
Still, there is at least no shortage of potential for reflection here. If you ever want to understand more about a thing, you know you can consider that that thing was made by Christ and for Christ, and that will give you plenty to think about.
Perhaps we can say one general thing that follows from these two. If Christ made every thing, and he every thing was made for him, we can say that every thing belongs to him.
There's a crazy thought! All those things that you look at and call you own, they don't actually belong to you. Did you make them? Do you know who made them, and for what purpose? This is telling us that if you were to have a conversation with Christ, he would say "Yes, I made that thing. Yes, I know it more intimately than anyone. Yes, I made it for my own purposes. Yes, it belongs to me."
Who are we to disagree?