And, er. ...Admitting to weaknesses, even small ones, is a show of trust. Which can be hard. On both ends. But being the recipient of that trust feels...nice. Usually. So it's not any trouble to do things for them. Because you want to--you are happy to be asked. Because it means they trust you. And trust is returned.
...There's more to it than that--other factors, situational variables and exceptions and whatnot, but. *clears throat self-consciously*