Also sometimes you don’t get rejected and instead get dragged into a 6 year long abusive relationship with someone with both borderline and narcissistic personality disorder and you end up with ptsd.
If it's a shy, non-commital "no", with zero followup explaining any reasons they don't want to, then sure maybe another ask is in order.
If it's a solid "no", or they start listing off excuses or reasons after a tepid no... They probably actually don't want it. It COULD be something like anxiety making them say, "no" and stammer out some weak excusable excuses, but that is rare compared to someone who just wants to politely say no.