I'm always so happy when the Lord gives us investigators, like last week when two 19-year-olds accepted the opportunity to hear more about the Restored Gospel, but the Lord also gives those same people agency. A lot of people we meet wind up not so interested in the end. But we keep moving forward.
Sometimes this helps me appreciate some Bible stories more. I might feel badly if an encounter that seemed really good in the beginning went nowhere in the end. But think of Saul or David ... they started great, the were the Lord's Annointed. And they went bad in the end. Just because an investigator doesn't get baptized or stops meeting with us doesn't mean we weren't blessed to meet them in the beginning.
We read in Alma that "the wicked remain as though there were no redemption made" because the only thing that can reverse the Infinite Atonement and its effects for an individual is that individual's agency to reject it. And so even people that the Lord gives to us to teach can reject our message, avoid us and give us false phone numbers. They have their agency, their right to choose how to accept God's gifts, and this is truly important. But the Lord will not cease to bless us as missionaries.
God wants us all to receive an infinity of blessings, but we cannot if we don't obey His commandments. I shared this recently with a member who has not been coming to Church much, and he bore his testimony that he knows the reason we go to Church and live the Gospel is so that we may be saved. It isn't just a matter of tradition or convenience or social gathering. But the Lord will not force us to accept His gifts. We have to come to Him.