The Investment of diminishing returns that hurts beyond yar wallet!

Sitting on the late train back home after a fruitful meeting; on board the MRT,
I'm wondering why sometimes in life how relationships between friends, love ones and kinships are often related with diminishing returns..

I had my fair share of great relationships and well, ones that would fall under the poor return of investment category.

Kinship to me, is the always going to be first and foremost the closest to my heart. An due to the nature of relationship being the closest to our hearts, it is becomes the most sensitive. Even through my extend family, I see the grimly returns of investments that the elder receives, reaping diminishing returns for their earlier investment in their child they love so dearly.
I count myself blessed that despite the occasional downs, the relationships I share with my immediate family has generally been loving and of great comfort. Despite the fact that it can be pretty laborious to maintain and build stronger bonds amongst family members; its already a blessing to be in a family that has generally avoid a diminishing return when it comes to kinship.

When it comes to friendship, I'm much more sceptical. From a young age, I realized that I never had a problem meeting new people and getting to know them. However, after a while, you realize its near impossible to have any form of depth in those friendships if your list of friends were easily in the hundreds. Learning to be prudent and calculative with the investment of time and efforts with friends have been placed me on a pretty challenging learning curve.
Recently, I must admit that when I took stock of the return of investments in my friendships, with a few exceptions, my performance were poor. Only a handful of friends are still in direct contact with me, and I hope most do get a pretty picture of my life. Sadly, its with recent observation, that I become more aware how often I become a doormat to 'friends' or taken advantage of for being available to their needs only at their convenience.
And that really means that I'm left with only a couple of healthy friendships with others.

Somehow it seems that the more I invest in certain relationships, the more it is destined to failure.

So where do I go from here? Hmm, I really am a little lost on this.
One of the best ways is to have no expectations when it comes to relationships. But try as I might.. It is a hell of a struggle not to wonder, not to care, not have a hope that this relationship that you're investing could be one that will a life-long one.

During this time of writing and reflection, I'm drawn to the parallels of how our Father, our creator, the lover of our hearts feels the same; the conflicted pain that I'm going through. Well, he gets it worst than me for sure. Surely, he knew about the oblivious diminishing returns that plagues the relationships that we face. He understands the heartache when we invest more of our love and get hurt in the end. What more about his perfect love for us, and our subsequent denial of him.

Could our father allow all of this to happen to us, to let us experience and draw us closer to him.. To understand his nature even more?

I know it does for me.