Imagine the following scenario: you meet someone in college, and when you graduate at 22 you don’t want to split up. They say sure, let’s live together, but we need to get engaged; if it doesn’t work out we can just break it off. After a year you realize your lives are much better together. You decide to get married but not to have kids until you’re 30. If it doesn’t work out you can divorce, but you sign a prenup and at least no kids would be involved.
If you both have clear and compatible career goals, that scenario saves you a lot of dating drama and gives you valuable support. I wouldn’t call someone in that scenario “weird.”