Microsoft Excel and analytical people go together incredibly well. I use it to record every gun I own, including date purchased, purchase price, MSRP, where I bought it, the caliber, serial number, who I want it to go to if I die, identifying markings, etc, etc. I've actually included everything of value that I own, or anything which includes a serial number. Of course, my laptop is included in the spreadsheet, so the file is e-mailed to myself every time I update it. I'll also print a hard copy or two and put those in a couple places.
Now if you want to talk about nerding out with Excel, I also have an Excel "program" which rate guns on how good they would be as carry guns. I have 30 or so fields with a certain number of points assigned to each, and I input the data of a particular gun and the program calculates a percentile for me.
I also have a program which I use to keep track of certain rare guns that sell (or fail to sell) on GunBroker. Buy-it-Now prices, reserve prices, bids, bidder names, winning bidders names, whether the original box and grips were included, condition etc. are all recorded. This gives me a good idea of what discontinued models are selling for in today's market, and what factors effect the price.
I have more time and skills than I do money.