“That’s one of the reasons I never wanted to get married. The last thing I wanted was infinite security and to be the place an arrow shoots off from. I want change and excitement and to shoot off from a Fourth of July rocket”.
http://i.word.com/idictionary/infinite
infinite (adjective)
immeasurably or inconceivably great or extensive
Helga feared the idea of being kept. Marriage would mean that it would last forever, and he would be there to secure her indefinitely. Helga was looking for excitement in her life. Whatever changes they were to be made were not to include a man that would stagnate her. Marriage to Helga would almost feel like she was being held hostage.