Smith won the 100 metres breaststroke on Monday and she looks well set for the double after topping the time charts in the 200m heats. She is defending the crown she claimed in Tokyo, where she said "life really changed" for her.
Smith won the 200 gold and the 100 silver in Tokyo, but set Olympic records in both events which shot her to superstardom, putting added pressure and expectations on her shoulders.
"It really forced me to think for my character as well, there were some ups and downs, but it really came down to the mental side," Smith told reporters.
"I feel like I'm in a much better space than I was in Tokyo, in terms of just really enjoying swimming for what it is. It's not my identity and it's not who I am, it's just what I do. There's life after swimming as well.
"I'm not going to beat myself up because of this. I'm trying to enjoy it as much as I can. I probably won't be swimming any longer. So I have two more races to go and then I'm done."
A household name in her home country, Smith is a serial medal winner in the World Championships and also the Commonwealth Games. She changed her surname from Schoenmaker after getting married in November last year.
Another medal will see her join Chad le Clos as the only South African to claim four Olympic medals, but she is the more decorated athlete with two golds already.
When the Olympic record holder was asked if she was definitely retiring, she said: "I'll tell you after the semi-finals.
"Every race now, I'm just enjoying and having fun. I think that the 100 really took off a lot of pressure in terms of a lot of expectation. So now this time I can really just have fun with my swimming and enjoy every single race.
"When I burn I can be like, 'It's okay, I have two more races to burn and I'm never going to feel those things again'. It's just makes me more excited to race."