Why would a guy take a girls number and not call her back?

I met a guy and we talked and things were good but then the topic of having children came up, he wanted kids and I didn't and it was a major clash. So I decided it wasn't a good Idia to continue the relationship but he asked for my number anyways and I gave it to him and he did not call but texted me saying he will reconnect after his travel back to home.. But he never contacted me back. Why did he want my number in the first place? I'm 30 and he was 41
Why would a guy take a girls number and not call her back?
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