i think that part of this is really just what you look for/at when decluttering. my husband tends to read each sheet in detail, then think over it. so ti is more emotional (and takes a lot more time), than simply making a decision and then sorting.
for example, your paperwork was over 10 years old. You don't need it for tax purposes, so no need to hold onto it. in such a thing, i would have simply looked for anything legal--such as when you paid a debt that was in collections. that could easily slip into the tax records for the appropriate tax year, and the rest could be shredded.
instead of agonizing over each piece of paper, literally and emotionally, you just shred away. it makes it quick and easy.
when dealing with papers, i start with the date--how old is it? if it is very old, and obviously not necessary for legal or tax purposes, it can go right into the shredder, no need to read or look at it. just letting it go. if it is newer (within the last 7 years), it might be helpful to have for tax purposes, and so needs to be looked at and filed appropriately. then you have to pay attention to the details of it.
but otherwise, the quicker the better, and the date can help.