"That's just how I am"
Many families have a story about it. "She's always been like that. At five she wouldn't let anyone do up her coat." It's told fondly, and it carries a claim, which is that you were born self-sufficient and nothing can be done.
I doubt it, and you can check for yourself. Look at where you do ask. You ask a shop assistant where the eggs are. You ring the IT desk. You pay a plumber, which is asking for help with an invoice attached. And many people who can't ask for themselves will ask on someone else's behalf without a flicker. You'd ring anyone, at any hour, for your child, or to get your team what it needs.
So the ability isn't missing. Particular conditions switch it off. For most people the conditions are that the request is for yourself, the person's opinion matters to you, and there's nothing you can hand over in exchange. A fixed trait wouldn't be so selective. Something that depends this much on conditions was probably learned.
Where you learned it is usually not hard to find. What follows is my interpretation, with some research behind parts of it.
In some homes, a child's request was met with a sigh, or "can't you see I'm busy?", or mockery, or nothing at all. A child in that position draws a sensible conclusion, which is that asking costs more than it gets. They stop. Nobody decides this. It just becomes the way things are.
In other homes a parent was ill, or overwhelmed, or drinking, and one child became the one who coped. That child was praised for it. "She's never any trouble." If being no trouble is what earned you warmth, then needing something can feel like risking it.
The study of couples from chapter 8 has something to say here. Some of the people in it were uneasy about depending on anyone, a pattern psychologists call avoidant attachment and trace partly to early experience. When those people had a problem to discuss, they tended to seek support in indirect and less effective ways. The couples were students and the study was a single conversation, so I wouldn't build too much on it. It does fit the idea that the habit starts early.
There are wider rules too. Many boys are taught that needing help is weakness, and many men still act on it. Michael Addis and James Mahalik, reviewing the research on men and help, note that men seek professional help for health problems less often than women do, and argue that how much less depends on the situation. In their account a man is less likely to ask when he thinks other men don't have the problem, when he can't return the favour, and when asking means giving up control. Much of that will sound familiar from earlier chapters, whatever your sex.
Many girls are taught that their job is to look after others, so asking for themselves feels selfish. Some families have a pride about it, of the "we don't take charity" kind. Some workplaces do too.
None of this is a life sentence. It explains the habit, and I think it also deserves some respect. The rule you learned was a good answer to the situation you were in. A child who stops asking a parent who sneers is being intelligent. The trouble is that the rule came with you into adult life, and one of its effects is to stop you finding out whether it's still needed. The people around you now are probably not the people who taught it to you. You haven't checked, because the rule tells you not to.
Perhaps you like being the strong one. It's part of who you are and you don't want to become someone else. I don't think you have to. Think of the most capable people you know, and I expect most of them ask quite freely. A senior surgeon asks a colleague for a second opinion on a scan. A good manager says "I don't know this area, talk me through it". Nobody takes either for weakness. The change I'm suggesting to your picture of yourself is small. You go from "someone who needs nobody" to "someone who can do it either way".
If you'd like to test this chapter, think back to the earliest time you remember asking for something and it going badly. Work out how old you were, and who it was. Then ask whether the people in your life today would answer in the same way. For most of them, I expect you already know they wouldn't.