The phrase "reality check" means taking a moment to think about or face the real facts or situation, rather than staying in fantasy or denial. It helps bring us back to reality and see things as they truly are. Full definition
This was the first time we had ever been in this situation, aside from a gathering of family or friends, & it was a kind of reality check for me. (lovethatmax.com)
This simple reminder on an everyday basis is a kind of reality check, which puts things in perspective for people. (theatlantic.com)
First, we think its a huge reality check in terms of what you're up against. (fairygodboss.com)