In my experience there is definitely a time when you know it. I was so afraid of assisted living and it was rough just thinking that the time had come but within a week I realized it was the best thing for everyone and more!. The fear was totally unfounded. The place had caring and competent staff 24/7 so right there it was complete peace of mind for me and my family. The facility was like a resort in that it had a 7 am to 7 pm restaurant that even made light meals on demand, snacks, ice cream, etc. outside of meal times, a big workout room with numerous pieces of professional equipment, a good sized swimming pool and lots of room inside and outside for walking, or wheeling in the wheelchair. I was fortunate that the place was only about 10 minutes away from me and family so we visited often and at anytime that suited our schedules. In this place there were married couples living there so maybe that is an option for your parents.