There aren’t many frustrations that feel quite like the one where you saw something terrible happening, did…

There aren’t many frustrations that feel quite like the one where you saw something terrible happening, did everything you could to stop it, utterly failed to stop it, and then years later hearing people talk about how it should have been stopped.

http://www.slate.com/blogs/future_tense/2016/05/26/gchat_was_the_future_of_messaging_why_did_google_make_other_chat_products.html