When the games were being released, comics were released covering what the characters were up to all over the timeline. One covered Garrus' childhood, his mother's illness, his time at C-Sec, and his vigilante days on Omega. When the gangs attacked, Garrus eventually got exhausted and called his father to say goodbye, his father tried to convince Garrus to treat it as just training and it will be fine. Garrus peaked over the ledge through his scope and saw Shepard arriving. With renewed confidence, Garrus promised his father that they'll talk again and ended the call, because the odds just got better.
Throughout the first game, everyone worrying humans were bullies that were trying to make a hostile takeover. By letting the Council, the heads of 3 alien governments die, letting 10,000 alien civilians die, and letting humans takeover the Council without a vote... Shepard proved that bias correct. Humanity is no longer welcome on the Citadel. Things would be a lot better if the Council were alive, everyone would love humans and treat Shepard as a hero.
Love your enthusiasm aaaand your well founded dislike of Cerberus. A little bit more combat gameplay would be good. The dialogue consequences and citadel race attitude to letting the council die, makes for a very different experience on Shepard's return. If you had saved the council the turian at the gun shop would have been fanboying over you so hard! It's great that the writers put so much effort into making your decisions flow through in so many ways. The Avina conversation would have been different too. Pro-tip: Overload, which you, Garrus and others does instakill flamethrower enemies, explodes them and damages close by enemies. V handy. It's just that you were a bit blocked when doing the shutter closing thing so your overload didn't actually hit the pyro. Emotional support tip: Romance Jacob not recommended. Kasumi's loyalty mission gets you the best SMG in the game, for that reason it's recommended you do it ASAP. Tobacco, the only significant thing humans brought to galactic civilisation...great!
