Canadian universities don't expect you to have your whole life mapped out when you apply to university. There are so many universities and choices. You may discover new programs after you apply or even once you get to university.
In many cases, you don't choose your major until the end of first year. This is great because it gives you a year to explore the many subjects at university before selecting a major. And there are some programs where you don't need to choose a major at all.
Once you start taking classes in different subjects at university or talk to friends in other programs, you may discover an area of interest you didn’t even know about. Or you may find that your program isn't what you expected or you’re struggling academically. That’s okay. You have a few options:
Switch your major
If you're not enjoying your major or it doesn't reflect your interests and goals anymore, you can often switch majors. You're never really locked into something that isn't for you although it may take more time and money (if you can't transfer all of your credits towards your new major).
Some universities will have no single rule about switching majors and how many credits you'll be able to transfer. Generally, you can transfer more credits going from a highly structured program with many required courses (such as many Engineering programs) to a more flexible program with not as many required courses.
If you're switching into a major that's unrelated to your original program, you may be able to transfer a lot of credits or you might need to start over as a first-year student. It really depends on the program you want to get into.
Programs that are competitive for admission from high school are usually competitive as well for switching into once you're a university student.
Add a specialisation or double major
Many programs allow you to take electives or add a specialisation in different subjects, so you can try a class before switching majors.
Or if you've already committed time and energy towards one major and don't want to lose that investment, an option would be to a pursue a double major. This isn't available in all programs but could help you keep the credits you've earned and add a major that you find really interesting.
Changing universities
In some cases, students find that the university they've chosen isn't for them anymore or their family circumstances have changed and they'd like to switch universities. It's possible to transfer between universities, although whether you can transfer some or all of your credits will depend on the university and the program you wish to transfer to.
Source: https://uwaterloo.ca/future-students/missing-manual/applying/changing-your-mind-what-study (accessed on 23 January 2024)