if you could mention it in your personal statement about how you've changed over the years and why it would make you an efficient OT, it should work for you rather than against you.
I'm just pulling this out of the air, but you could say something like, "as an undergraduate I lacked motivation and direction, but as I have developed through the past several (however long) years I understand how important motivation is in achieving goals and progress. I have acquired a level of dedication I never had during my undergraduate years, and I hope to convey this same level of dedication to my patients in improving their quality of life." ooooor something like that. just make sure that for every experience you talk about, relate it to WHY it would make you a great OT.