Finnish word jollen comes from Finnish en, Finnish jos ((subordinating) if.)

Detailed word origin of jollen

Dictionary entry	Language	Definition
en	Finnish (fin)	The first-person singular form of the negation verb. The English translations include do not/don’t and not (with auxiliary verbs and be).
jos	Finnish (fin)	(subordinating) if.
jollen	Finnish (fin)	If I ... not, unless I.