Riding one's bike as a transportation tool to go to work/school is quite different to using the bike to go on a leisure rides. The main difference is with cyclo-commute, you are going somewhere daily (or frequently). There's the time factor too. Now that you are retired, there's no time factor to arrive somewhere nor there is a primary reason to ride to a destination. Over time, you will just said to yourself "ahh... why bother. To heck with it. I think I want to go golfing instead".

So I would highly suggest that you do some volunteer work. Give back to the society. Say volunteer at a library, local community centre, etc. Now then, there is a purpose to go and "Commute". I hardly think riding to a local coffee shop has the same effect as true commute.