Do guys ever regret not committing to a girl?

Would a guy ever regret losing a girl because he didn't want to commit? Say for instance this girl was down for you like no other even you acknowledged her loyalty and the way she hold you down during a rough time you went there. She was always there when you needed her but she came to a part where she wanted commitment and when she asked you you wasn't ready so she left.

Would you regret letting her go?
Do guys ever regret not committing to a girl?
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