[jppope]

This is fine investment advice... but the post isn't asking for investment advice. It's asking for advice on fighting lifestyle creep. Besides, there are a variety of ways to invest one's money, why provide only one vehicle as advice for investing?

[AnimalMuppet]

The "invest most of it" was the way to fight lifestyle creep. If you've made it "disappear" into a Vanguard fund (or whatever), then you don't have it "available" to tempt you into spending it. You set your budget/expectations/lifestyle for what you have left after investing most of the surplus.

[mortivore]

I think the idea is to give a very clear route for fighting lifestyle creep. Sure there are other options, but this is actionable advice. The question was also asking how do you do it so it may be how that user fights lifestyle creep.