I dont know who told you that a real honda engine "breaks in" at 100,000 miles, but they were full of ****. Granted that their engines last IF PROPERLY MAINTAINED, but you cant REALISTICALLY EXPECT more than 200,000 miles for the life of the engine without a major rebuild.
For "average drivers" 100,000 miles take about 7 years. This is longer than the average length of time that a new car is owned. (4 years) As second owners tend to not take care of their cars as well, the cars dont last as long. (its a fact) My friend's dad is a honda mechanic, and according to him, if a honda has mechanical problems, they show up in the first 500 miles, other than that they seem to stabilize in terms of gas mileage at around 2000 miles.
Now here is the kicker, the more expensive of a honda that you buy, the shorter it lasts. The S2000 and NSX have high revving engines. (the s2000 reds at something like 9k) again, maintainance is everything, but if your engines spins 3 times as much as a normal engine, you cant expect equal wear over time.