How can you lose lane with Teemo?

I mained Teemo and when I see a bad Teemo I want to jump from my window.

1. How can you be bad at Teemo (0 skillshots,ranged top laner,3 abilites)
2. How are you able to lose lane with Teemo,if you just poke them with your q on lvl2 when they want to last hit,you can't lose lane. 3.There is no counters to him,Darius can be but if you bait him into your R and poke him you will win ez. So I am just wondering how is it possible to lose lane with this champion,even ganks aren't a problem just place your R in river and when jg comes to gank he will step on them (sometimes if you place 3 shrooms near each other he can die without you doing nothing)