What is a "step-pulse" or how to study when in college

The hubby and I had lunch with a friend on Friday, and in the conversation during lunch, the most effective way of studying while in college came to the topic. So S. turned to me and said "what is a step-pulse?" For this to be funny, you have to know the "rest of the story". But before I go there, I will have to tell you what a step-pulse is. A step-pulse is a synchronization tone/pulse between 2 pieces of equipment (usually electronic) running at slightly different speeds. Think the tones you hear when sending a fax, or for those of us old enough, the sounds of a computer modem dialing in to our internet service provider (isp). Those tones you hear are a type of step pulse, and make it where the machines can talk to each other. The story begins when S. and I were dating, he was in the navy, in school to do electronics. I was a single mother, trying my hand at college again, and we were hanging out more than was healthy for either of our study habits. But on this particular day, S. hands me his text book and says "quiz me on the things on this chapter for class tomorrow." So, in typical college teacher fashion, I looked through the chapter, found the most obscure fact in the middle of a lengthy paragraph and said "what is a step-pulse?" He responded with "honey, they won't go that in depth. They won't have time." I replied with "you are in college now. They expect you to read it all and pick out what you think you need to know. I think you need to know this." So we both learned what a step-pulse was, and continued on with the day. The next day, when in class, the first question out of his instructor's mouth was "What is a step-pulse? Anyone know?" S. was the only one who did. He came over after work, told me about it, we got a good laugh and thought no more about it, until... Some of you may know that in the military, to advance, you have to take a test to prove you know your stuff, both militarily and job-wise. So, you fast forward, we were at our first post school duty station, and he was up for promotion. He goes in, takes the test, and guess what is on the test?! Yep, you got it. "What is a step-pulse". It was on that test, and every single advancement exam he took his entire 12 year naval career. He's been a civilian for many more years than he was in the navy, but we still giggle over that. And when we had lunch yesterday with the same friend and her family, one of the things she said was "and she taught you what a step-pulse was!" Her husband had not heard the story, so we gave him the abbreviated version, and giggled once more. So if you are ever asked "what is a step-pulse?" now you know!