You never know if you've quit running for good unless you've sustained a debilitating injury that physically prevents you from running.
I've quit running "for good" a few times.
I competed at a high level for a few years after college.
Once I determined that I wasn't going to try and race at that level anymore or go for PRs anymore, I totally stopped running.
There didn't seem to be any point to make a half effort at running to go slower.
Then some local road race comes up that you think about doing for fun and you run a few times a week and jump in.
Then life happens and you get a job where you would have to go out of your way to find time to run and you pass on that.
But would still run a little.
Then got a serious girlfriend and had no time to work and see her all the time.
Then got a job where I could run during my lunch break and got back into running for two years.
Then hurt my achilles pushing it too much in a race where I should have dropped out.
At that point, I quit "for good" again.
But a few years later rehabbed it and did some more running.
Then would schedule a race now and then but would always hurt something.
Now the key to running a few times a week is to not schedule any races.