Just realized my brush angle was the reason I kept wrecking caps

Been doing chimney work for about 6 years now and I always thought the cheap fiberglass rods were the problem when it came to cleaning terra cotta caps. Took a job last month in Columbus where a homeowner had a cracked cap that looked like someone took a hammer to it. My usual sweep would have been fine but I kept chipping the inside edge on every pass. Finally a older guy on site told me to drop my brush angle down to almost flat instead of riding it at 45 degrees like the videos show. Switched mid-job and the difference was night and day, no more gouges, cap stayed intact, finished in half the time I budgeted. Makes me wonder how many caps I've blamed on bad material when it was just me holding the rod wrong. Any of you run into a basic habit that took forever to unlearn?