Taylor spilled the deets to Barbara Walters for Barbara Walters Presents: The 10 Most Fascinating People of 2014, airing on ABC on Sunday, Dec. 14, at 9:00 p.m./8:00 p.m. CT.
"You have such a good reputation," the celebrated journalist, 85, began in her chat with Swift, 24. "You have never been 'the bad girl'… You don't drink. You don't smoke."
"I mean, I do drink, I am 25," interjected Swift, who will celebrate her 25th birthday on Saturday, Dec. 13. "So it's not like, I mean… Yeah, I was at a Knicks game and I had a beer and everybody was like, 'Ohhh!' I was like, 'Tsk.'"
"I did wait until I was 21 to drink," the Grammy winner explained. "I was so paranoid about getting in trouble or setting the wrong example or sending the wrong message."
"I put every one of my actions through a filter before I do them because that's the way my life is," Swift continued. "That the reality… If I do something reckless or thoughtless or careless, or I treat someone badly, that doesn't just affect me; it affects that person. Then, if that story gets out, or some 10-year-old sees that I did that in a news article… my actions do have ripples."
"It's kind of a nice thing to keep you in check to live a good life," she said. "It's not like some gilded golden cage that people make it out to be. Living your life the 'right way' and trying to make 'good decisions' is not necessarily some horrible penalty."
Swift is rumored to be dating 1975 singer Matt Healy but nothing is confirmed.
"I don't see a scenario right now, the way my life is, in which it could work," she told Walters of being in a relationship. "So I don't think about it because I don't like to think about things that I can't solve."
Walters said to the singer, "You seem very sane… It's not that fashionable all the time… You seem very centered."
"I think all the time about big concepts in my life," Swift explained. "I don't have answers for everything and that doesn't scare me. I think the reason I am sane is because I have a really good family who are all very sane, in the midst of all this kind of insanity surrounding my life. That really helps -- it really helps -- cause I can talk to them about it and they are gonna be very honest with me about it. But always, always really supportive."