Reverse engineering, is like the process of taking apart a built Lego set to see what parts have been used, and how they have been used to build it. Now, while the term "reverse engineering" has made it into the very niche subcategories of technical engineering, I'll be talking about the reverse engineering everyone does in their lives, probably without even noticing it. 

For example;

Let's say you're in your childhood days and you have a favorite toy, a remote-controlled car. You might be curious about how it works and you decide to reverse-engineer it in your way.

First, you would observe its behavior closely. You might notice that when you press different buttons on the remote control, the car moves forward, backward, left, or right. You might also observe that there are lights on the car that blink in response to certain commands from the remote.

Next, you would start to form ideas about how these actions are achieved. For instance, you might guess that pressing the forward button sends a signal to the car telling it to move its wheels forward. Or you might speculate that the blinking lights are controlled by a separate circuit that reacts to signals from the remote.

In that way, you could even reverse engineer how you live. 

Reverse engineering isn't bound to tearing down a Lego set or even a UFO. It's the method of observation and trying to understand and correlate the information you receive.