The one time that I did, I was sitting idle for a long time one evening and got up very abruptly, finding that my legs were completely nonfunctional for
just long enough for
me to collapse. I didn't pass out, I just had zero leg strength for
a few moments. Fortunately I hit nothing and just landed on the carpet, getting up after I recovered and went about my business. Never happened again. If I've experienced an overall weakening, I haven't noticed it.