Telling people not to make their dream game. If someone really wants to attempt something, let them. Many here are hobbyists with next to no intentions of becoming full time game devs or getting rich.
Does it really matter if they never finish? Not really. Does it matter if the end result isn't as good as they imagined it would be? Again, not really. However, if they enjoyed the experience then they haven't come away empty handed.
I think encouraging folk to work on things they have no interest in, though it might sound like sage advice, might make them throw in the towel even sooner than they would have if they had just stuck with their dream game. Because who wants to waste weeks or months (most likely of your spare time) doing something you don't care about?
Oh my GOD so much this!
I see it all the time, for every newcomer, and you know what? It's total bull crap.
Screw it. Go right in. Give your fantastic story ideas the space they need to breathe. Use two hundred plugins. Do it all - allow feature creep. Go big and overblown.
Some advice is so counter productive to creativity, and this is the big one.
You absolutely don't need to get something "under your belt". You don't need to make something small and crap before going bigger. You don't even need to learn the ropes.
A year ago I'd never dabbled in Ruby, JS or RPG Maker. Ever.
I went straight in. I didn't even know what an event was. I didn't know where the phrase RTP originated (which, for newbies, doesn't even exist anymore. They mean the default assets).
I now have my dream game well underway, with a great battle system, loads of plugins, artwork and music I've bought and paid for, complete evented sequences which look, sound and work great. I've got 46 weapons per category across six different categories, 48 dungeons, 20 towns, six playable characters, a good world, a great story, some fantastic lore...
Every time I want to do something, I learn on the job. I've thought myself through trial and error how to create cutscenes which work across multiple maps, how to use parallel Vs auto events, I've evented my own mini games, my own pop up reward and notification system, and worked with fantastically talented people's plugins.
If you want to make your dream game, just do it!
It reminds me of when I was eleven and I wanted to learn to play guitar. Everybody said the same thing:
"You have to learn acoustic first, and learn some theory".
When I asked why, there wasn't a suitable answer. So I ignored it. I got myself the electric guitar I wanted. Got the amp I wanted. Played what I wanted.
Now I'm a virtuoso, self taught on everything from tight, clean rhythm to sweep picking. Do you know when I got my first acoustic guitar?
Two years ago.
It was a birthday present.
So if you can ignore one single piece of crap advice just once in your life, it's this:
Start small.
There's enough time for that when you're retired.
Make what you want to make now, while you can make it, while you have the fire and the passion.