"Because I don't have runes"
Why do people think you need runes to jungle? You don't need ANY runes to jungle.

Because if somebody else DOES have runes for it then it would make more sense?

Depends on who you are jungling with that you need rune's with and your starting items.

There are reasons you don't see level 1's jungling. If you don't have runes and/or masteries, you're at a HUGE disadvantage. Not only is your own jungle weaker, you're also counter jungled far easier.

Not to mention some champions actually still do need runes to jungle. Not all, but there are some that if they don't have them, they're dead.

Well Basically Runes Give u more Advantage If u don't use that , Well u are playing with Disadvantage, That is all

There is a large difference between killing killing jungle mobs with [b] every two mobs and actually jungling. For many champs, armor runes are this difference.

There's also the difference between clearing the jungle, and actually keeping up in level. Damage runes often make this difference for many champs.

At lvl 1 runes can help make jungling at easier. You can get an extra 30 atk dmg just from runes alone. I've also seen some other crazy stuff of alot more atk dmg, health, or ap.

You need runes to jungle. you can just die to giant wolves without the right runes.

Unless you're Udyr, Skarner, or other top tier tanky jungles GF

You can do ok with full jungle mastries in normal. But DON'T JUNGLE IN RANKED WITH NO RUNES.