I am curious how those who haven't mentioned lumpy expenses, accounted for them? There are some major expenses that only land every 10-20 years like replacing a roof, replacing cars, replacing AC/furnace, etc. Reviewing your last 2-4 years won't capture them?
In the past, we were forward thinkers, and after years of tracking expenses with Quicken and kind of knowing where we were spending our money anyway, we gave up using Quicken as past history was fairly useless due to all the one time variable costs that were showing up, and somewhat unplanned. I knew our fixed costs just from habit alone (taxes, utilities, insurance, food, auto maintenance, etc). Forward planning for very large expenditures was not part of the Quicken exercise for us.
Since we always attempted to make sure we had enough non-retirement savings money to cover "lumpy" expenses, we just talked about when they would be expected to happen and planned on that spending. We never kept a detailed "budget" as our life was not that predictable. Plus, we were a "blended family" at that time with up to 5 kids at home or in and out from time to time.
Past spending was just that, history, and a good portion of it probably won't repeat due to life changes (kids at home, multiple cars, heath issues, etc).
For instance...."our roof is 15 years old and is starting to look bad. I guess we should plan on replacing it within the next 5 years or so lets make sure we have enough funds to cover it then." (and we did just that) Halfway intelligent people should be able to figure out when a roof is in bad shape (or should be) and when their cars are nearing their useful life (maybe I am wrong here, though). I'm looking at lumpy expenses being those which cost several thousands of dollars, not a few hundred for a TV or appliance.
Even now in retirement, I (widowed now) really don't keep a detailed budget plan as I have enough to last for quite a long time.....actually, much longer than I expect to last!
Lumpy expenses are just that, lumpy, and I'll handle them as I go along the path. And all those 30 years of Quicken files are sitting on my old desktop never to be looked at again.