Yes, that seems to be a common problem with the equation. Nearly everyone knows it, few people could actually use it. I remember that I, too, also didn't actually know how to use it. As I picked up some physics here and there during my studies, it became clearer.
A large portion of understanding physics is getting the units right. It might seem tedious when teachers at school and tutors, professors etc. at university insist you always write down the units, even when only calculating something trivial like speed or how far an accelerating vehicle gets in a given time. But once you get used to it, a lot of it becomes clear. Units are like numbers which with you can calculate. In the end, when you cancel down the result, you usually get rid of some m, kg, s, etc. and the rest is some handy unit, like m/s, kg · m²/s². Was really an eye opener when I first realized this.
It's also handy in chemistry when calculating the concentration etc. of stuff.