I visit relatives in Connecticut and Florida 2x per year and make other visits. I've had obscure questions asked over the years by both USA and Canadian border officials, but no biggies.
FWIW, avoid hypothetical & silly / stupid discussions of contraband, terrorism, bringing back too much stuff while you wait in line to be checked, the borders have very sensitive microphones aimed to catch words that should prompt a search of you and your car. I had a boss once whose wife worked this job, well before 9-11 and this stuff was in use at most CAN/USA crossing points.