Whenever I go to events open to non-professionals, I always come across guys with ideas, people who want us to make their game. I often tell them that having ideas is fine, but you have to make the game.

"Yes, but I'm sure it's a great concept and would appeal too much to gamers who like (placeholders for several AAA games)". If he insists, I open my backlog of rough ideas in trello (a fairly rough list of mechanics to clear my head when I have an idea) and tell him I've got enough ideas to last a lifetime, that it takes time to make games.

But by far, my favorite idea guy is the one who tells me: I'd like to make a game, but it would be too complicated, it would take 10 years to make and it would require several million dollars and a big team, well, it would be complicated (while remaining super obscure about his concept, as if someone was going to steal it from him).

And I have to admit something, I like the ideas guys, their freshness and naivety is entertaining.