Apparently my little sister is determined to become a teenage mom

[LSLGuy]

An infant, and even a 10yo, is better described as an unconditional obligation. One with considerable rewards, but a vast obligation nonetheless. As this current thread explains:

What are things that non-parents cannot understand?

As a single person in my 30s with no kids, I’ve heard or seen comments quite few times to the effect of “You don’t understand (this or that) until you have kids yourself.” Or, a non-parent simply cannot understand what it is like to be a parent. Etc. So…for parent Dopers…what are these things? I’m sure it’s not usually a reference to practical things (i.e., most non-parents know perfectly well not to let a kid play unsupervised with a loaded handgun or leave kids in a hot car, while even some p…