My tracks

You can run more than one. A problem you've solved counts on every track that contains it, so starting a second one never costs you work you've already done.

Add another track Overall progress

Two kinds of reset

Start again puts you back at the beginning of a track. Your record of what you solved is untouched, so problems you've already done still show as done.

Forget my attempts deletes the record itself. That can't be undone, so it asks first, and it's never part of starting a track again.