it should be solid by the time you actually fall in love and consider your self in a relationship. the reason is;; when you 1st meet someone you don't know them so how on earth can you totally trust them? even after a month of knowing each other you have not even scratched the surface of getting to know the other person yet. the trust is not "just there" it has to be earned. for example; i was going out with this guy for 3 months,i cared for him BUT i still did not trust him 100%. i have only know this individual for 90days! so i did my research and found out he had a woman at home= there was no trust= he did not earn my trust.