When it rained you became soaked, including the cheap little feather sleeping bag that would remain wet, so you were wet in your bag all your clothes were wet, the ground under you was muddy and soaked, and the tent didn't even prevent you from getting directly rained on because every place on the inside of the canvas that you touched, became a small fountain of water pouring through.
Many of us would just quit bothering with them, and just sleep in the rain when we were exausted.
They were tiny, so soon after entering they were dripping all over from the contact with the canvas, so it was cold mud under you and water running on you, while you just waited for the day to start so that you could escape the nightmare.
Precious memories, how they linger.
We worked so hard at putting trench around our little tents. Generally wasted effort. Better to just roll up in the thing as one more layer keeping moisture and cold away from you.