Is it a myth that you shouldn't eat late at night?...

[Emphasis]

The goal is to lose the bit of fat on my stomach and put muscle on, i am a relatively skinny guy though .

I'd say add some cardio to help with that. Eating your regular healthy diet will keep your weight where it is normally at, and the running will help shave off the unnecessary fat.

As for the topic question; I know I'm just repeating what others have said, but yes I've found that if I eat late I am more prone to gaining weight easily. I'm also naturally thin. It's whatever your goals are.

[Coeco]

I wouldn't call it a "MYTH" but it's rather scientifically known that you burn the least calories during the night and most during the morning, so if your goal is to loose fat, don't eat at night.