Replying to the last email I sent in a thread: TO: field should have the other person's address, not mine

Replying to the last email I sent in a thread: TO: field should have the other person's address, not mine

Example:

#1 john@email.com sends me an email
#2 I reply.
#3 I realize I want to add something. I press reply on the email #2. In the new email's To: field my own email address appears, which is bad.
Obviously, when I'm adding a new email to an email discussion, I want to send it to my partner, not to myself.

In short: if I press reply on an email sent by me, it should put the other person in the To: field, not myself. I believe that's how Gmail works too.