[Q] File structure questions topic

Hi all,

And yet another noob question...

The problem of being this ignorant, is that it is also hard to ask a good question. So I'll have to tell the story in full...

I started to use custom ROMs only one month ago. I installed and configured CWM 6.0.4.5, and through ADB PUSH to /sdcard/ I put the files for CyanogenMod 11 "cm11.zip" and "cm11_gapps.zip" into my phone. I was able to install this ROM, so no issues there.
After some time of playing around, I felt that some bugs in the ROM were unacceptable to me. I also got errors that stated that my memory was full, although, when I looked into ES file explorer or even the standard 'Storage" tool in android, my phone appeared far from full (+5 Gb free!). To me, that was the drop to remove this ROM (althoug I already found out that it was not the ROM's fault...).

So I installed another ROM, CM10.1.3. Again, I ADB pushed the files "cm1013.zip" and "cm1013_gapps.zip" to /sdcard/ , rebooted into recovery. There I did the following:

- install zip
- choose zip from /sdcard

At this point, I thought I would find my files "cm1013.zip" and "cm1013_gapps.zip", but I didn't! Instead, I did find the previous files "cm11.zip" and "cm11_gapps.zip"!
However, I did see a folder "0/", so when going into that one, I did find my files... So I continued the installation of my ROM, no issues.

But now, when I use ES File Explorer, I can't find these "cm11.zip" and "cm11_gapps.zip" anywhere! It seems like once I'm in my ROM, I can't access a complete part of my memory.

This means I lost a big chunck of my internal memory!
What did I do wrong, and more important, how can I resolve??

I tried my best to search this forum, but all I came up with was this thread:

http://forum.xda-developers.com/show....php?t=2304138

Interesting, but not a solution to me, as I'm unable to even find the files in the first place.

All help much appreciated, and sorry for the (too) long explanation.