If a man took on responsibility beyond his age in his formative years, he will be less likely to want to commit to serious relationships: because relationships manifest to him in the form of responsibility. He does not see the love; he sees only the responsibility.
I interact with old men a lot. Many successful, a few troubled. Yet something is almost always common with them: They do not recall specific happy, or sad moments. They only remember their responsibilities. What they had to do, what they did, & how it impacted their communities.