In my Philosophy class's reading of Descartes, we just got to the part were he wonders why a perfect God would create beings who are so imperfect as the likes of us. Descartes came up with several possible answers, as have I, and since I can't now remember which ideas he wrote about, I'll just throw them all together and explore the question freely without worrying about citing my sources.
Firstly, how do we know we're not perfect? Sure, we make plenty of mistakes, but we learn from those mistakes, as God intended. We're not great at everything, but maybe we don't need to be. We know that God has plans for us, but we don't know what all those plans entail. Maybe He has planned for, and is planning on, our occasional missteps. Perhaps our "imperfections" are features that help make God's plan a perfect one.
Or maybe they're just cosmetic. In my Art History class, I learned that when artists got bored of hyper-realism, they invented whole new art styles built on deliberate imperfections. Impressionists, Surrealists, and Abstract artists painted images that didn't reflect how the world really looked but that carried deeper meanings to them. Many of them could have made perfectly realistic-looking paintings, had they wanted to, but they didn't. As Descartes said (and I'm paraphrasing), even a perfect craftsman doesn't have to make all of his creations perfect. Sometimes, "good enough" is good enough.
Plus, we have to take ourselves into account. A lot of the mistakes we (or at least I) make on a regular basis are our (on at least my) own fault. God gave us the freedom to choose, and He's not going to force us to make perfect choices all the time. That was another guy's plan. God is willing to let us make our own choices and learn from the consequences. That may be the best if not only way for us to learn and grow. And our growth is the goal here, not immediate perfection. He wants us to become perfect eventually, but in order to become perfect, we first have to not be perfect. And we're following that part of the plan perfectly so far.
There is a lot we can gain from our imperfection, like wisdom, humility, and the quirks that help make us unique. Rather than hating our imperfections and wondering why God allows us to be so flawed, maybe we should look for the silver linings and learn what good can come from our being currently imperfect.