I just found the answer to one of the most pressing questions of my life reading through my ‘Decision Analysis’ notes. We tend to miscalculate the long-term impact of decisions that will have an influence many years from now. To rationalise why it is harder to make friendships as we grow older, we do not have ample opportunity to grow together in the friendship like we did in childhood (for a billion reasons that I couldn’t bother stating at the moment, maybe for another post) which means that it is a gamble, implying a higher discount rate needs to be applied in evaluating present worth of the relationship. Also, since as humans we have unreasonable expectations, we expect to derive the same level of satisfaction from new friendships as we do from the old ones, we can imagine the NPV to be the same. Given the shorter time period we have with new friends (up to the end of our lives), there is only one way this can be made possible – We simply have to invest much more effort (annual cash inflows) in these new relationships now than we ever did before as we have lesser time with people we meet beyond our school/ university years and we’re expecting similar quality.