At the beginning of its treatment of Step 10, the Big Book of AA says:

We have entered the world of the Spirit. Our next function is to grow in understanding and effectiveness. This is not an overnight matter. It should continue for our lifetime.

It is strange how, since it was first written, this has come to mean that we are now to work the "maintenance Steps." How are we supposed to grow if we are only working "maintenance" Steps? We perform maintenance on our cars, but we don't do it because we think it will make our cars any better -- we hope rather that they will wear out a little less quickly. But wear out they surely will, whether we maintain them or not.

Growing in understanding and effectiveness is not likely to come about if we treat Steps 10, 11 and 12 as a mere repetition of the first nine Steps. The Big Book is telling us that we are at the start of something, not the end. We are beginners again, not ageing experts.