Why do i never get the experience lead

Hi. A plat 5 jungler here. So if i jungle, most of the times i get a 15+ cs lead. While my enemy jungler is still the same level. But got a kill already.

Here is a scenario that happend a few says ago. In the early game the enemy cho gath had arround 8 cs. But 2 assist. While i had 35 cs but no assists. And we had the same level... So, i don't really understand it, did he just tax 2 Waves in every lane? Or am i missing something