Does the flux in solder really get old ?

I have some of the older 60/40 flux core that is over 20 years old and
never had any problems with it.

Just getting into the SMD soldering and the tubes of solder paste have
an expiration date on them of about a year and some want to be kept in
the refrigerator when not being used. Also bought some liquid flux and
it mentions an expiration date about a year or so later.

Just being a home user it may take me years to use the stuff. I know
lots of things have an expired or use by date on them,but that does not
really mean much. I think the government just requires a date on some
items.