>>535434024
The wind.
Genuinely, the wind is what knocked Tails' bullies away and the wind is what inspired Tails to learn how to propel himself at high speeds with his two tails as Sonic Origins shows.
The wind inspires Tails and gave him what he needed to believe in himself Tails in turn propels the wind to reach new heights. After all, somebody will be waiting for him. Tails wants to fly high, high enough to reach the highest of all the heavens.