There’s nothing that evolves relationships faster than working and spending so much time together in a non-personal capacity.
Plus, both Galecki and Cuoco, who is now married to equestrian Karl Cook, each had their share of relationships following their initial separation which helps too.
That being said, their timeline may have been sped up because they continued to work together for almost a decade after breaking up.
Kaley Cuoco and Johnny Galecki dated from 2008 to 2010, which is probably the right length of time for most people to be unapologetically happy for an ex moving on and having a kid with someone else.