Yeah, there is a HUGE difference between being able to change out jewelry and being ready to stretch.
I like Corazon's advice on getting some nice jewelry at your initial piercing size. This way you will know what kind of jewelry styles you like, and by taking your time you will be able to take in how large you want to take your earlobes. I took 5 years to get to 5/8" because I was content with the smaller sizes for a while... and sometimes I miss my earlobes being at 00G