Lying about something usually involves an amount of rationalization, justification, denial, & refusal of the truth.
i don't know why people do it about anything. i know why i used to do it and who helps me to not do it today.
As far as my clean time, i never have and never will lie about it. i am very grateful for the amount of time & effort i (and countless others!) have put into my life to help me achieve 3 years, 7 months, and 27 days of total abstinence. i would sooner pick up a drug or drink than to dishonor those who have helped me stay the course thus far. i would rather walk out in front of a truck than to disgrace the God of my understanding by treating my clean time as something trivial and unimportant. i would prefer to chop off my left nut than to tear my heart apart by lying to myself about such a precious gift. By the way, everyone's invited to my four year celebration on Febuary 5th!