How Honest With Kids?

A Mother’s day article a few weeks back posed an interesting question: 

Some months back, I was invited to a party with 20 or so other mothers. … a few of the women began reminiscing about their own youths, comparing the transgressions they’d committed in their teens and 20s and debating whose were the most egregious. … As we pursue the goal of protecting our children from some of our more boneheaded and/or high-risk antics, we face one of the essential dilemmas of parenting: What do children need to know about their parents’ pasts, and when do they need to know it? …

So, should you admit to your child what you’ve done? … If you cop to something, anything, will this give your children tacit permission to try it all? Remarkably few — if any — researchers have explored this topic. … So it’s odd, really, that there is no consensus on what to do when one of the million little interchanges involves the question of whether the parent is — oh, say — familiar with the taste of strawberry-flavored rolling paper. Experts, exploring their own gut instincts, differ. …

And let’s face it: Parents lie to their children all the time, offering up many comfortable fictions. When we read them fairy tales, we are, in a sense, lying. When we lead them to believe every story has a happy ending, we are lying. Our culture puts so much emphasis on frankness and sharing that it’s easy to forget the real uses of evasion and stalling and deftly changing the subject, which are social skills on which civilizations — and, sometimes, families — rely.  Because the truth can be harsh and destructive, and why force it upon them?

So how honest should parents be with their kids about their younger "indiscretions"?