What would you think if you were told to work for someone else for half the year, then allowed to work for yourself?

Sounds a bit like serfdom? Yes:

A freeman became a serf usually through force or necessity. Sometimes freeholders or allodial owners were intimidated into dependency by the greater physical and legal force of a local baron. Often a few years of crop failure, a war or brigandage might leave a person unable to make his own way.

In such a case a bargain was struck with the lord. In exchange for protection, service was required, in payment and/or with labour. These bargains were formalized in a ceremony known as "bondage" in which a serf placed his head in the seigneur’s hands, parallel to the ceremony of "homage" where a vassal placed his hands between those of his lord. These oaths bound the seigneur to their new serf and outlined the terms of their agreement…

Hmm. Did not that sort of thing die out a long time ago?

No.