13 years in and I finally learned how to seam carpet correctly

Been installing for 13 years, mostly residential in the Phoenix area, and I always thought tight butt seams with a power stretcher was good enough. Last month a homeowner called me back because a seam in their living room started lifting after 8 months. Turns out my seaming iron was way too cool and I was basically melting the glue instead of activating it, plus I never used a seam roller with enough pressure. A buddy of mine who does commercial work watched me do a seam and just said 'you gotta run that iron slower, man' and it clicked. Has anyone else had that moment where an old habit turned out to be your biggest weak spot?