I want to be a runner but.......

I am finding that I need to make a decision as to what that means. Running is an important part of my life and I hope to be able to continue until my last day on earth. (shooting for 100 years!) There are two directions I can go. I can set goals to run races I haven't yet done, such as a full marathon or a 50K trail race. I have two half-marathons under my belt, one 25K trail race and too many to count shorter races including 15K's, 10-milers, 10K's and 5K's. To reach these longer goals would require a lot of training, at least 3 or 4 runs a week. I would need to curtail some of my other fitness activities to avoid over training. Not sure I would want to do that. My other alternative is make the decision that running a marathon or a 50K don't really need to be done. I can do my Spin classes, walk,hike, practice yoga and do a nice long run on the weekend and enjoy it all. There's also cycling which I haven't done for a couple of years. My nice Trek 1000 is up on the stand and just begging to go for a ride. So maybe it doesn't have to be all about the running. Now I know that there is a danger in choosing the second alternative. I could just be 'wimping' out and may always regret never having done a marathon. I don't think I am quite ready to make a decision yet.