Honesty goes a long way. I simply told them I was very young when I had that position and did not fully understand the ramifications and importance for being to work on time and my tardies eventually tallied up enough occurrences to terminate me. Which is why I am always early to everything now. -He did make an effort to say he appreciated my timely arrival at the beginning of the interview.
My answer: I have had the opportunity to work for multiple world class companies in a successful consultant role. I have gained knowledge, experience and skills that I would have never been exposed to if I had worked at one company for many years.