So much this!
By lvl 10ish id say that you know most of the moves and abliities of 70+ champs. By lvl 20, you should know the counters to almost all champs. Its crazy how much diversity there is in this game and at the same time, its very balanced.
Just got done playing with Dragonite and BeezKneez. Raped first game, 2nd game, the support kept ksing hardcore and stealing the ADC and APC's gold.