If I was awesome, I wouldn't be in Silver just now. If I was awesome and could dominate with a Karma Jungle I would be in diamond already, but I'm not. When you're playing with other people who are equal in skill level and you get a troll, an afk, a dc, or a feeder on your team, that's just enough to tip the balance. If the one game I was in didn't have an Ez that was just meh instead of feeding and trying to solo the other team, it would of been enough for a win.
Eventually, I hope to be good enough to carry hard and dominate everyone with a Sion mid, but until then, there is shit that just ruins your day.
Seriously though, there are just some games that aren't savable, especially when you have 3 people on your team where two are trolling, one is high as fuck as doesn't have the coordination to turn around, it's just time to try again another day. Most of the time, people come here to blow off steam, but then you get the people here who tell them they suck. Good one there.
I suppose that's why people always preface "Oh I'm not good at this game but..". So they don't have to read another guy telling them they are a shitty player.