Once it happened when I was in my 5th or 6th class. Dad got consession voucher from school for travelling from HWH to VSKP. My height at that time was like I was fully occupying the SL berth.
The TTE came and went but there was a spl checking around VZM. There the spl TTE asked for my birth proof. He said seeing the height I am not a 6th class student. My dad told if I am not 6th class student then how come school gave the voucher for consession on the ticket? The TTE went off soon. Else few TTEs make the life hell if we fear or don't know the rules of railways...