I am 58 years old. I have been running since I was 10 years old. I have ran in grade school, JHS, High school, open and the rest of all divisions till now which I am in the last of all divisions "Senior" I ran because I love it, it is my passion and I love to compete. I dont do road races but cross country, outdoor and indoor track. From the hills of my former country of Colombia south American till now, the streets of Syosset Long Island I still get up in the morning (5 am) and do my first run. Then after a heavy and highly stressfull day, I do my training run. I do this because it has become part of my life; like brushing your teeth, taking a shower, eating, reading etc, I just got used to do it. But also I have goals and objectives that I want to reach again (Long island Championship, US championship and world masters championship) But regardless of either win or loose, I just want to do well, get good at running. After 48 years I am still learning the "art of running" But after all of these years, I have done it and have taught myself to do it on my own. No training partners, no coaches, no sponsorships etc. It would have helped to have running and training with others but in the long run I have become tougher and I know in the end I still will be the one STANDING!! Discipline and rely on yourself, I guarantee you will succeed.
I might have run against you. I'm 60 and used to live on Long Island (left about 12 years ago).
I have very rarely run with anyone in the last 10 years ago. I enjoyed being part of a big training group at a club in England years (made things like 20x400m much easier!), but also like being able to arrange my day to just train when I feel like it, rather than being committed to a certain time.
I stay motivated by racing, and trying to slow the decline as much as possible. I don't have any problem getting myself out to train - I actually feel bad when I have (a planned) day off.