Keeping It Clean
Ernest Hemingway once said, "I write one page of masterpiece to ninety one pages of shit...I try to put the shit in the wastebasket." And just like writers, programmers also manage to produce quite a bit of shit. Of course, most programmers are perfectly capable of recognizing when they've created an inelegant function, but because of time restraints and deadlines, they just keep on going. But students that are still learning to program, often have trouble recognizing when code is in desperate need of deletion.
A university-level programming class usually requires students to spend a great deal of time working on projects and homework. So its quite easy, after hours of coding, to become emotionally attached to one's code. Generally, a student programmer will make a mistake in a function or block of code, and so they'll add in a quick little fix. Eventually, after numerous little fixes, their function starts to become a giant, awkward, lumbering behemoth that is still wrong.
The most obvious choice is to simply, as Hemingway so succinctly said, "put the shit in the wastebasket" and start from the beginning. But the student has managed, after hours of labor, to become extremely attached to their hundred lines of awkward code and just can't manage to throw away the terrible result of all their hard labor. I say this because when I was learning to program, I often found myself becoming too attached to my code. On one particular occasion, I spent two days patching up the code for my self-balancing AVL binary tree, which was frankly, a piece of shit. Eventually, I threw my AVL tree class in the garbage, started again from scratch, and recreated a working tree class in a few hours. If I had only been a little more emotionally detached, I might have realized how stupid I was acting.
In order to keep code clean and effective, student programmers need to learn to stop falling in love with their misshapen code-children; code cannot love you back, so don't waste your time developing emotions for it. Just keep it clean kids, and save the loving for another time.