The first time we paid cash, we sold two properties when we combined households, and bought one together. It was kinda funny, because we hadn't planned on paying cash. The mortgage broker pissed us off (didn't lock the rate when we specifically asked them to, in person. Of course, rates then spiked.) We looked at each other and said, fuckit, we're just gonna pay cash. We still kinda regret doing that.
We had to overbid 12 other bidders to get our offer accepted, but it was one "highest and best" offer, no back and forth*, but back then paying all cash wasn't quite the bargaining chip it is now.
IIRC, at one point someone wanted "proof" of where our fresh money had come from, so we just hauled in all of the escrow paperwork from the two recent house sales.
Before anyone gets their very intelligent DPOYM panties in a pretzel, we have three other properties with long, low mortgages on them. We re-fied them about 2.5 years ago, so they still have 27.5 years to run, and we have no plans to pay them off early.
We paid cash for a less expensive property two years ago, and it was a breeze in comparison. We had "aged" cash on hand, because it was our seed money for our next RE project.
*That's only if you don't count the additional $35,000 the selling bank (it was a short sale) tried to bilk squeeze out of us at then end of an eight-month escrow. We got the call late on a Friday afternoon. By Sunday, DH was leaning toward agreeing, until I pointed out that he could buy his wife a very fine used car with that kind of money. We held our ground, and it finally closed.