My beadboard backsplash looks crooked but it's actually the wall

Finally got around to tiling the backsplash in my 1982 ranch outside Cleveland. Measured everything level, used a laser level too. First row went up and I could see a visible gap growing toward the corner. Panicked thinking I messed up the layout. Pulled out a 4 foot level and checked the countertop, then the wall. Turns out the entire wall bows out about 3/8 of an inch over 6 feet. The level was right, my tile was right, the house just settled weird over 40 years. Ended up using a fat bead of thinset on the low side and it came out fine. You can only notice it if you put a straight edge against it. Anyone else run into surprise wall issues that made you redo your layout mid-project?