I scrutinized Allen Cheng's successful Harvard Application many times and I read examples of others who got admitted into top universities and I noticed that they all had one thing in common. All of them took rigorous classes in high school pertaining to their subject of study but they weren't in honors classes like I am. They took classes which were more rigorous than honors classes. They were in senior or junior honors classes as freshmen, and Allen Cheng seemed to have done the same.
These examples have led me to ask the question, how rigorous should the classes I take in high school be? Do top universities expect me to take higher level honors classes or will they be fine with me taking honors classes at my level and showing extraordinary competence in my field of study?
Taking classes designated for higher grade levels may be a common theme amongst people who have been accepted to high-caliber universities, but it's not necessary for admission. There are plenty of students who simply perform well in honors classes at their grade level throughout high school and go on to be admitted to the most selective schools in the country. I can attest to this from personal experience; I was accepted to several Ivy League schools without taking any junior or senior classes as an underclassman.
If you're interested in taking a higher level class in a subject that you really enjoy you should go for it, but if you stick to honors classes at the expected grade level you shouldn't be concerned that it will ruin your chances. Taking the most difficult classes available to you at your grade level and earning As is enough to get into these schools if they're also impressed with your test scores and extracurricular achievements.