What should I delete from my history

[Fragile Bird]

I see that I have every notification I ever received, and every post I ever liked, and other stuff. Is this weighing down the servers? Would you admins rather see us deleting all that stuff? I know one answer is, keep whatever you want, but it still begs the question, would it be better if I didn't. I assume most people keep everything because there doesn't seem to be a reason to delete everything.