Returning after 2.5 years - Reset?

You can try going through every level separately using the self-study quiz, before doing a full reset. That way, you can identify from which levels you still know most of the stuff and then reset to the highest level where you had decent results so that you don’t have to go through all the levels again. It’ll probably take some time, since you’re at level 35, but less time than starting from level 1 again.