Yes, I understand.
Unfortunately, since my old computer doesn't work anymore, I have to go and check my AI files, one by one and see if they open in AD, Those, that were not saved with include .pdf option, wouldn't open in AD. I can subscribe for AI for 1 month for $30, save them with pdf option, or in pdf, and then drop AI subscription. Some files are pretty old, in CS3, so right now I have no idea what options were included back then. To save time, I think I better do everything in one batch, save as AI with .pdf option and go from there.
For now - I'm learning my ways around AD.
PS. Those Adobe subscriptions are insanely expensive. I got my CS5 just shortly before they started all this subscription business and I never subscribed to them.