I too am a nerd. I am in my element when I am playing with numbers so a spreadsheet combines two things that I adore (spreadsheets and fashion). What could be better?
I actually get a lot out of the practice though. For example, I know exactly how many items I own in every defined category. This informs my buying decisions. I always want to buy more bottoms, but I really need more tops. I know what colors I own and that dictates color purchases. I know what brands work for me and what brands I should avoid in the future.
At a glance I know exactly what is in my wardrobe and if I am having trouble deciding what to wear on a given day, a quick review of my spreadsheet usually provides an answer.
Counting allows me to calculate cost per wear. This is very valuable information as well. I was able to define spending caps for certain categories of clothing. For example, if I buy slacks that exceed my personal spending limit, I will never get a reasonable cost per wear for them. In contrast, I discovered that I use my bags so often that I actually could increase my spending limit on bags by several hundred dollars. I feel confident that I will easily achieve a reasonable cost per wear for my bags. So I adjust spending limits throughout the year and I have the basis to support those spending limits. You can't really dispute hard numbers.
I not only count the number of times a garment is worn, but also when that garment is worn. This shows the seasonality of some of my clothing. Some items have really short seasons and I want to remember I own them during that short season and make a point of enjoying them when I can.
Finally, I can easily see when certain items are not being worn. If I still love that particular piece, I make it a point to ensure that it gets worn more often.
I am certain that there are other benefits as well. These are what I thought of off the top of my head.
