There are several reason whey tomatoes plants do not form flowers. It may be because the weather is too hot, the plants were given too much nitrogen or from lack of water. If your plants "grew and grew" I suspect they had a soil or fertilizer rich in nitrogen. Tomatoes need a balanced plant food. I use Osmocote plus at planting time so they get all the micronutrients plus the phosphorus and potassium they need for flower production. Gardening is an adventure and we all keep learning so try again next spring. Keep growing, Marianne Binetti