Have I really grown up?

As I sit here in a new environment, learning new techniques, talking to new people, feeling quite by myself, a cloud of thought submerges me into the ground. I am restless from within, but this feeling isn't new. It is, on the contrary, far too familiar. And hence frustrating. I have faced this feeling too many times, and had thought I had grown out of it, learnt from my lessons. For a long time this cloud didn't visit me, and I thought I have finally outgrown it, finally shielded myself from the world's insensitivity. But the sad part is, I know deep within that the world isn't so bad. Its always me, the sensitive one. The one who cares too much about other people, and then gets hurt. The reason I get hurt is because I always end up expecting an acknowledgement of what I did for you. And that's because I always do that, make it a point to reciprocate and prioritize that. Is there no one else like that in the world? There are people who seem to be like that for a while and suddenly change, leaving you surprised. Ive tried to be attached and not expect in return, but failed each time. I thought I had learnt it the hard way though, thought I had managed to curb my natural instinct of getting attached, getting excited and expecting the others to feel the same. And for a while I know I had nailed it - I had not experienced this restless frustrated feeling for a long time in the not so distant past. At times I missed being me though, I missed being the fierce friend that used to be, missed being the person who would do anything for my friend. Because that is what gave me real happiness. It came with a price each time however, and so I slowly adopted the defensive front. And it was hard. But it was perhaps better than getting hurt? I wasn't sure, until again, recently, I was reminded that it definitely is better than getting hurt. Again I had let my guard down, got excited, felt passionate, went out of the way for some people and started giving without thinking. This time, I decided I am not going to think twice, I am just going to do what I feel like, show my love and not be inhibited by worldly masks like formality. But, this feeling was too good to last. Within a week it all came crashing down. I felt unwanted, felt used and felt unreciprocated. And to hell with being logical and sensible and blah and blah. I felt all these things in flesh and blood, so there has to be a reason for it, isn't there? People come find you when they need you, when they have nothing else to do, and you let your guard down and go all out for them. But again and again, every time, when its their turn to reciprocate, to build the relation, their priorities go elsewhere. Everyone goes their own way, does their own thing, but Im the one always trying to include others, make them feel involved, make them feel at home in a home away from home. But the whole point is, this is not something new, its far too established. I have been taught this lesson a million times, feeling equally hurt each time. Then why the hell do I let it happen again? Why do I give some people so much importance? Why do I end up feeling an affection for someone and act upon it? Why am I this way? Can I NEVER learn? Do people never grow out of these things? Have I really even the slightest bit and will I ever really, in this sense, grow up?