20s are defined by The Fear of Becoming: the frustrating realization that you may walk through one door, maybe several, but that also means giving up on hundreds of other potential other doors you could walk through.

30s are defined by The Fear of Not Becoming: the terrifying realization that 3/4 of those doors are just painted on the wallpaper, the half of the remaining ones disappeared into thin air, and the remaining half starts to lock-up and barricade, damn fast too, regardless if you've made your choice or didn't, so it will require ever more effort to walk through any of them.

So you stand there, in the corridor, still paralyzed. With a melting ice cone in your hand dripping all over the red carpet.