The Importance of Runes

The first time i jungled, i decided to watch a guide. A jungling guide. So i watched the guide and i was look "oh cool." so the guide said, start gromp and smite it. I did. ( I also got a leash ) at the end, i had some health left. then I had to go get Blue. I tried to kill blue as possible as i could ( which mind you it wasnt possible ) at Level 2. And I died. I was wondering why i couldnt get blue buff and i looked at the guide, he seemed to have more armor then i did. So why do these guides never state the importance of runes? It pisses me off how people underhandedly underestimate their runes and never mention it when they're doing a jungle guide. They should give out a warning or something saying "HARDCORE RUNES NEEDED FOR DIS" but they just act like newcomers aren't going to watch the video and all they'll be doing is dying. 10/10 jungle guides. i could understand if your using jax or some other ez junglers with a lot of sustain.