Your current name reflects how you feel about yourself and which attributes in your personal makeup you consider most prominent. It's most important influence is therefore in the areas of self-confidence and self-worth. 

The current name is also the only part of your chart that can be changed. You can't change your date of birth, nor your birth name - they are already registered and even if you legally change your birth name, numerology doesn't view that as making any difference in your chart. However, you can change the name you use today, the way you introduce yourself, and although the impact is minor, it can be crucial to the way you feel about yourself, which in turn greatly affects the quality of your life. 

As a rule of thumb - and there are certainly exceptions - if you want to change your name, consider choosing a name already in your family and thus connected to you through your ancestors. Those characteristics are already present in your lineage, which makes the new name easier to assimilate into your personality. 