There are two major differences. For one, the compiler can force you to check for None. Trying to use an Option<T> as a T is a compile-time error, you have to

There are two major differences. For one, the compiler can force you to check for None. Trying to use an Option<T> as a T is a compile-time error, you have to write the pattern match to use the Some case. For another, and this is the big one, you can write a function which takes a T, and you can't pass it an Option<T>. The compiler can statically confirm if your variable has already been "nil checked". I used to write a lot of Java code, and since you can't know for sure that null-checking has been performed (among other reasons, that might change with a new code path) you just kinda sprinkle it everywhere. And still forget and get runtime errors.