I budget to the penny - not because I need a budget to keep my spending in line but because I like perfect records. It helps with tax planning, keeping track of my savings rate, trend analysis, and more.
I've received a few referral bonuses from credit cards, some from referring my wife and some from referral posts here and elsewhere on the internet. Those bonuses are going to be taxable, so I have to include them in income on my spreadsheet, but then I don't know where to put them in expenses. My spreadsheet defaults to put any money not assigned to any expenses to go into misc savings. However, there is no money unless I cash out the points. I've thought about putting that money in under the vacation line item, as that's where it'll eventually be used. However, I haven't previously recorded signup bonuses in the budget. If I'm going to record these taxable points as vacation funds, then I should record my other points as nontaxable income and vacation expense as well. Doing so will also bring my savings rate down a couple percentage points.
Basically, life is chaos, and putting everything in neat little boxes is not as simple as I'd prefer.