Can a major rejection affect you for years?

I go on dates but don't make them my girlfriend. I tell them on the first date or so that I'm not looking for anything serious. I don't care about love nor commitment nor believe in it.

Whenever my close friends joke about when I'm going to settle down and have kids, my reply is an ''They day you all go to the moon on a space shuttle''.

Even though I appear as hardened and anti-commitment to everyone, I wonder if this has something to do with the past even though I rarely think about it by now. I was 22 years old at the time. My then long time girlfriend since my HS years (we met when we were 16) rejected me. She wasn't sure if she saw herself growing old with me, needed more time and gave out more excuses. We've been together for 6 years and she still wasn't sure. I stupidly thought she was the one. I've offered her the highest level of commitment (was willing to risk it all) and she rejected it, rejected me as whole. Truth be told, if she had said yes then I would've already been a father.

Is this true.. that a major rejection can affect you even years later and change you, change your views, your personality etc?
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I've never experienced the ''falling in love'' emotion ever since. I've never loved another girl since. I'm just not able to. It's like my brain shut down completely and I couldn't feel that emotion since.
Can a major rejection affect you for years?
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