What purpose do things like exception handling and encapsulation have as a solo developer?

As someone who is new to C# (and programming in general), I am learning it by experimenting with small solo projects. As I continue to learn more about C# specifically, I come across topics like encapsulation (to my understanding, the process of only allowing as much access as is needed, and doing so in a way that prevents others from breaking your code) and exception handling (to my understanding, catching code-breaking exceptions to either allow a program to continue running or to provide a more detailed explanation as to what went wrong, the latter of which may involve throwing exceptions manually).

My question is, other than to learn best practices from the beginning, are there any reasons someone working alone would want to consider these things important right now? Because to my understanding, they don't seem to affect the actual functionality of a program. You can change all access modifiers to public in a program and it will still work the same way? Additionally, I don't really need a more detailed error message or have to worry about people misusing and breaking my code if I am the only person I am writing the code for. I am not against learning these things from the beginning as I have been trying to use best practices in my code, but throwing manual exceptions especially doesn't make sense to me as someone working alone.

Both are good habits to get into, even if you're working alone.

Setting things private or protected means you'll keep them enclosed within your function, so you can understand the function is only meant to be used within the class. It'll also not show up in Intellisense, when it's outside the boundary of the access modifier, to prevent accidently misusing them.

And Exception Handling overall is useful, if your program crashes unexpectedly, the catch exception will help you to figure out what goes wrong, or can help keeping the program running after the crash.
Crashes are also possible to happen after release, Outside your debugging enviroment. So it'll help if these crashes are notified or logged down for other users, or even for yourself.

That said, you don't need to put everything into a try-catch() as long as you expect that it'll run that section without problem, but consider using it on sections where it could be less stable (like connecting with external sources, or creating and saving files).

And overall, getting into these habits will make you more suitable to work in teams in future.