Meeting former classmates gives everyone an opportunity to see how they have all changed. People grow up in different ways once they leave school, and this is often apparent when they attend reunions. There is always someone who was incredibly focused on studying and making good grades. They may have learned this mattered less than they believed, and they have adjusted their outlook on life. Some people might have been completely disorganized during their school years. During their life after graduation, they might have learned how to keep their life on track for success with great organizational skills.
Meeting old friends who were close school buddies is always a bonus at reunions. It gives people a more solid measure of how they have changed, and it allows them to see how their lives have improved. Some people have learned to let go of old habits. Others have become more laid back, and they enjoy their newfound freedom. They might be the perfect fuck buddy for an old flame.
People generally are not looking for a new relationship when they attend a class reunion. They want to appear successful, and being unattached is not seen as a sign of this. Being validated in the opinion of former classmates is often thought important. There are always rebels, and these are the type of people who are fuck buddies. They laugh at the need to be validated, and they seldom try to impress their peers.
Few people are ever willing to admit their life is not perfect, and attending a class reunion makes them anxious. Those who require no peer validation often live more open lives. They do not want a relationship, and they choose no strings attached sex because it is a lifestyle choice they have grown into over the years.