The word Lent comes from the old English word for lengthen, as the days are getting longer at this part of the year (in the Northern Hemisphere). I suspect that is where the 'pagan origins' come from, although I have never come across that 'origin' in relation to Lent in my reading.
The 40 days are significant because that signals something momentous. Interestingly, 40 days is also enough to form new habits, so there may be a psychological bent there as well.
Carnival, or Mardi Gras is the day when food forbidden in Lent is used up...meat, eggs, butter, etc. The Orthodox and Eastern Rite churches still fast strictly during Lent. The western Church has modified significantly.
Sundays are not included, officially, in the fast.
I am working from my own memory at the moment so forgive early morning lapses. I am not teaching this year...
Jaye
