I'm going to tell you a story, and I may ramble a bit, but I swear it relates. When I was 16, my parents gave me their car so that I could get a part-time job. The first rule was: "If you are driving, and there is a girl in the car, she must be in the back seat. If she is driving, you must be in the back seat. Not because we dont trust you, but because appearances may cause someone to doubt and stumble."
I was closing one night at the fast food restaurant where I workded, and it was very late. One of the older women that I worked with was unable to get a ride home, so I offered to take her. I was too embarassed to ask her to sit in the back seat, and since it was 3am in the morning, who would know? Besides, she was older than my mother. My father woke me at 8am the next morning to ask me "Who is this strange woman was that you were seen driving around town?"
The point is this - it is a VERY small world. You may not be talking to anyone from your past, but that doesn't mean that they wont see you "accidentally." We all know that JW's are encouraged to spy on each other, and the glee that comes from discovering someone doing something they shouldn't. All you are doing is delaying the inevitable.
I have deceived my parents and my "friends" so many times, I cannot even count the ways. It took me a long time to get out of that pattern, and sometimes still find myself lying even when I dont need to. Do yourself a favor - DONT start. You are hurting yourself in ways that are difficult to heal.