Even the deepest submissive has tremendous difficulties--at first--with learning to obey and to submit, because learning to be a good submissive is not a matter of personality or willpower (although these things help). It's not a matter of being "submissive enough." It's entirely a matter of training and experience. The most willing and compliant submissive isn't born knowing instinctively how to serve or how to put her master's needs first. In fact, she's taught from childhood to be independent and willful. Overcoming a lifetime of cultural conditioning takes lots of time; and nothing in the easy fantasy play that people do on line or over the telephone prepares them for the difficulties of actual, real-life daily obedience.
The only way a submissive learns to be a good submissive is through extensive practice, through making mistakes and learning from them, through talking over what goes wrong with a knowledgeable and patient dominant, and through extensive and informed assistance from her dominant partner.