Play Mid to Carry

My current style of "carry" is mostly playing a solid game and pushing objectives and assisting in team fights as an ADC or jungle. The downside to this is that my power spike comes more mid game and lasts to end game. Early game I don't have the farm or exp to fight a mid/top laner as a jungler and an ADC I need to build my items. It's pretty common to run into games where 2 or more lanes feed before level 3 at which point the game is mostly over.

I've seen smurfs carry by simply running into the enemy jungle and somehow fight 1 guy and then somehow be slippery enough to maneuver around the eventual other 2 enemies that come to help. They either escape safely somehow or get a double or triple kill. Rinse and repeat. I'm usually too busy with my own game to be watching what they are doing. Sometimes they lose because they have 15 out of 23 kills on the team and the score is 23/13 and enemy team catches up. Champs I see them do this with, annie, cassiopia, ahri, yasuo, fizz. It seems to me that to carry like this you need to play mid.

I feel learning mid is the key to "hard carry" but it seems like a completely new game from JG/ADC and I've been kind of lazy to "start over". This is my observation corrections/tips appreciated.