I know I've certainly been back and forth with both my kids. Aptitudes and interests and personality can make such a huge difference in how they appear on any given day or in any given situation. My DD's Ruf level estimate turns out to be pretty on track with her recent testing results, but I certainly questioned myself a lot when she was younger. Now my DS is 4.5 and I'm back there again, trying to figure him out, scratching my head, and never sure what to think. I am right now trying to decide whether to apply for early entrance Kindergarten for him (he is 7 weeks too young to make the regular cut-off, but they will test kids born in the 3-month window after the cut-off).
