Hmmm, idk. I know marriage in my 30s is something i actually consider ideal and hope it will come true, but it may not be ideal to everyone.
But one thing which I think everyone should consider is to start working out and building muscle mass, specially that your 30s is an age where you start losing the mass gradually. If people prevent it from happening that early, and invest in themselves, i believe they are investing for their future, old self. Imagine how many problems regarding movement, muscle deterioration and bone fractures could be prevented if people take care of their health early on.