Bhai, its diwali season for the time you have booked the ticket. For festive seasons people can plan as they know they will have holidays just like you planned. Along with you 100s would have logged in for that 18 seats. Whose luck would have been mindblowing got it CNF/RAC. Others got WL tickets. These scenarios are very common during diwali, holi, durga puja, ganesh chaturthi. Check in trains from mumbai to konkan for ganesh chaturthi, in 5 min 1000s of seats got booked and all trains are in WL, some as long as WL 750 +.