Im 15 and i´m doing my own game and i have been doing that game for about 1 - 1,5 years now. I keep on going cause in reality i want to be able to make my own game solo.
Then i loose my motivation too so i stop coding for a while and then when i have my motivation there again i start making my game 
and while i dont code i learn, watch youtube videos about Unreal engine and so on.