This dream seems to carry significant emotional weight and can be interpreted in several layers.

1. Desire for Change: The time machine symbolizes your desire for change or the opportunity to revisit past decisions in your life. It reflects a longing to improve your current situation or to escape from challenges you are facing. The young people represent potential and the possibilities that lie ahead, which you feel you have missed out on.
2. Parental Influence: Your parents' apprehension about the time machine suggests that you may feel constrained by their expectations or beliefs. Their insistence on you not using the machine could represent societal or familial pressures that prevent you from pursuing your own dreams or desires.
3. Regret and Reflection: The lamenting about missing out on the opportunity indicates feelings of regret or a fear of lost potential. Seeing the young people as adults living happy lives may reflect your worries about your own future and the paths you haven't taken.
4. Perspective on Adversity: The reassurance from your parents and others that it could have been worse suggests a coping mechanism you might be adopting in your waking life. It points to a recognition that while you may feel regret, there are always positive aspects to consider and that adversity can lead to growth.

Advice:

• Reflect on what opportunities you feel you are missing in your life and consider how you can pursue them despite external pressures.
• Communicate with your parents about your ambitions and desires; understanding their perspective might help you find a balance between your aspirations and their concerns.
• Embrace the idea that every decision, even those you may regret, contributes to your growth and learning. Focus on the present and the potential future paths rather than dwelling solely on what could have been.

This dream serves as a reminder to evaluate your choices and to seek a path that feels fulfilling to you, rather than simply aligning with the expectations of others.