[jpatokal]

to run toward me screaming with excitement after I'd been away for awhile

Hint: That's not a 0-4 month-old child... and that's because dad took his four months off after mom had returned to work.

[Domenic_S]

I was confused myself, to be honest. Eventually worked it out that this was later in the kid's life (who goes to a playground with a 0-4 mo old?), but it was a little confusing.