Why was graduation an important moment in your life? 3 reason

I don't think that the Graduation ceremony is of much importance as long as you get your High-School Diploma. However if you want 3 positive reasons:

1.After many years of repeating, failing exams or got held back several grades its good to finally know your work paid off by going to the Graduation when you see all your friends with there graduation uniforms, saying last goodbyes, you feel self-satisfied of finishing your 12th grade and earning a reward for it, etc. 

2. You can spend some of your time with family members that day. Everyone is congratulating you because you finished your 12th grade and some want to give you good advice in what you can or want to do with your future

3. Also those people who have helped you along the way want to grab the opportunity to celebrate your achievements as well. Graduation gives you all the time to stop and appreciate this moment together. 

However to be honest if you just get the diploma and not assist its good too. Why would you want to see everyone cry like if it were a funeral in such a happy day? Not trying to make of this something negative though.