What do you think about me skipping my 20 year high school reunion?
Is there a reason you want to skip your reunion?
I don't like seeing all my friends get old.
You're no obligated to go to an event if you don't want to. A lot of people get better with age so you might want to think about going to see how well everyone is doing.
It's not like I have to.
This is a once in a lifetime event and it would be great for you to catch up with old friends. However, it's not mandatory and if you would be more comfortable not going that is fine as well.