Never be Enough

Everything is never enough

I have this but I want that, but when I get that, I want the old one

When I was 5, I wished I was 20 or above, but now when I'm 18, I wish I could go back a couple years

When I was busy with my study, I desperately wanted freedom, wishing I don't have to go to school anymore, but now when I have a super long holiday (waiting for graduation day) like months, I wish I could go to school again, feeling the rush, the joy, the sadness, the craziness.

It simply cannot be understood (well, for me at least)