diff --git a/postgres/README.md b/postgres/README.md
index 43dea809c..0fdbd9ae4 100644
--- a/postgres/README.md
+++ b/postgres/README.md
@@ -189,7 +189,9 @@ See the PostgreSQL documentation on [`pg_hba.conf`](https://www.postgresql.org/d
 
 ### `PGDATA`
 
-This optional variable can be used to define another location - like a subdirectory - for the database files. The default is `/var/lib/postgresql/data`. If the data volume you're using is a filesystem mountpoint (like with GCE persistent disks) or remote folder that cannot be chowned to the `postgres` user (like some NFS mounts), Postgres `initdb` recommends a subdirectory be created to contain the data.
+> **Important Note:** when mounting a volume to `/var/lib/posgresql`, the `/var/lib/postgresql/data` path is a local volume from the container runtime, thus data is not persisted on the mounted volume.
+
+This optional variable can be used to define another location - like a subdirectory - for the database files. The default is `/var/lib/postgresql/data`. If the data volume you're using is a filesystem mountpoint (like with GCE persistent disks), or remote folder that cannot be chowned to the `postgres` user (like some NFS mounts), or contains folders/files (e.g. `lost+found`), Postgres `initdb` requires a subdirectory to be created within the mountpoint to contain the data.
 
 For example:
 
diff --git a/python/README.md b/python/README.md
index d2cb8d90d..3fbb264eb 100644
--- a/python/README.md
+++ b/python/README.md
@@ -176,7 +176,7 @@ $ docker run -it --rm --name my-running-script -v "$PWD":/usr/src/myapp -w /usr/
 
 ## Multiple Python versions in the image
 
-In the non `python:slim` variants there will be an additional older `python` executable at `/usr/bin/python` while the desired newer `/usr/local/bin/python` is the default choice in the `$PATH`. This is an unfortunate side-effect of using the `buildpack-deps` image in the non-slim variants
+In the non-slim variants there will be an additional (distro-provided) `python` executable at `/usr/bin/python` (and/or `/usr/bin/python3`) while the desired image-provided `/usr/local/bin/python` is the default choice in the `$PATH`. This is an unfortunate side-effect of using the `buildpack-deps` image in the non-slim variants (and many distribution-provided tools being written against and likely to break with a different Python installation, so we can't safely remove/overwrite it).
 
 # Image Variants