Bill, 16, had a curfew of 10:30 that night, but when the hour arrived, he was deep into studies at one of the college libraries here that stay open until midnight. He finally came home at 12, pleased with the work he had accomplished.
His mother was not so pleased. An argument followed. Bill listened to his mother's complaints, then went to bed. ''I didn't feel guilty at all,'' he recalls.
Both mother and son were angry with each other. Both felt they were right. Was there a way out of - and in the future, a way around - such a confrontation?
A conference here entitled ''Bridging the Gap,'' sponsored by Emory University, brought several hundred parents and teen-agers together recently to explore such questions. Several other similar conferences are scheduled this year in the Atlanta area.
The idea of bringing parents and teen-agers together to tackle issues is not new, but few groups actually do it. Some schools and community groups involve youth and adults, but usually on specific problems.
Bridging the Gap conferences are aimed at a much broader target: closing gaps in communication, whatever the topic, between youth and their parents.
''Parents and kids wish the same thing,'' says Robert A. Hatcher, an Emory University physician who organized the conference. They want children to reach adulthood uninjured, not addicted to a drug, having passed their course work and , in the case of daughters, not pregnant, he said.
The ''gap,'' he said, is ''between what people want to see happen and what happens.''
But sitting in on two of the parent-teen discussions here provided some examples of how better communications between adult and child can lead to an improved understanding on some of these issues.
Some of the teen-agers in the conference had these suggestions for parents:
* Don't compare one child with another. Recognize individuality, and support the good qualities each child expresses.
* Don't be overprotective.
Said one girl: ''It's nice to know your parents want to protect you.'' But most of the teen-agers pointed out that eventually they would have to deal with whatever issue the parents wanted them to avoid. Better to help them develop a sense of values to apply to the challenge than simply try to avoid the issue, they said.
* Don't be negative. One girl said her parents fail to praise her A's but complain when she gets C's.
* Listen. One boy said he and his father could talk about ''anything.'' He praised his father for being informed about the problems young people face, including drug abuse. But most of the other teen-agers said they have problems talking to their parents.
* Show you care.
Said one boy: ''No matter what happens, tell them (the teen-agers) you care.'' And don't yell, said a ninth-grader, or the caring ''never gets through.''
Parents in the meetings also had suggestions and comments, too.
* Don't fuss too much about minor issues. Otherwise, ''when you get to a really big issue, you've used up all your credibility.''
* Explain decisions. (Many of the teen-agers complained that their parents do not explain decisions.) ''When I'm asked 'why,' instead of saying automatically 'Because I say so,' I have to come up with (reasons) A, B, C,'' one mother said.
* Parents don't always ''want to know what's lacking in the family,'' said one mother, commenting on what she sees as a key reason for children using alcohol and other drugs.
''Sometimes teen-agers are better listeners than adults,'' says Carolyn Hatcher, a moderator of one of the discussion groups and a former high school dean of students, recently named commissioner of parks and recreation for Atlanta.
One way to open up dialogue, Mrs. Hatcher says, is to use the phrase, ''I don't know,'' indicating a willingness to hear another point of view.
Despite the differences of opinion, there were signs of common ground at the conference. Bill, the teen-ager who told the conference about the curfew incident, later admitted that there was a way to avoid the argument. On a different occasion he had allayed his mother's anxiety by simply calling home to ask permission to be late. Mrs. Hatcher told him, ''Your independence will do you well as an adult.'' But she also expressed approval of his parents for caring about him.
Speaking for both generations, one mother noted: ''It's not easy to grow up; it's not easy to be an adult.''