Arabic vowels

It is the weirdest thing - I have great trouble distinguishing long and short vowels in Arabic, although the difference between them is quite audible, and it is more pronounced than in English. Actually, in English there isn't a set of long vowels and a set of short vowels that are exactly the same as the long vowels, just shorter, per se, it's just that some are longer and some shorter.

Russian certainly doesn't have a distinction between short and long vowels, so that is one reason for me having trouble in Arabic.

I don't remember that I had any trouble with English vowels, but it was so long ago that I am not sure if I ever confused 'beach' and 'bitch' or 'sheet' and 'shit' (why are those contrasts always so amusing?). I certainly do not do that now.

Anyway, the question is, why would I confuse the vowels (or not remember the difference, I can certainly hear it) in Arabic, while I don't do so in English?

Excited

The first book I will be reading for my area studies class is

Arabic culture through its language and literature

M.H. Bakalla, 1984, Kegan Paul International.