My family and close friends "keep me grounded."

[sitifan]

The people you choose to have around you make all the difference. My family and close friends keep me grounded. You have to have a mind of your own and a strong head on your shoulders. Cricket is the most important thing to me, so the rest of it pales in comparison.
https://www.jiemengz.com/authors/26368-9/
What does the expression "keep me grounded" mean?

 

[emsr2d2]

This link should help.