Recovering my account on StackExchange

Occasionally, I lose control of my account on StackExchange. I don't visit for a few months, I get logged out by some process during that time, and, when I try to log in, it tells me my password is incorrect.

When I go through the "forgot password" process, get the recovery email, and reset my password... I then get told I'm about to create a new account on StackExchange. I actually did that once, many years ago, and trying to figure out how to combine the accounts was messy.

It's happened again.

How do I reset my password without creating a new account? StackExchange has always been a little bit like High Dark Magic to me. Its account structure seems more confusing than necessary.