Why are some jalapeno peppers not hot?? This is very frustrating!?

Every afternoon I have a delicious snack. I have a plate full of vegetables, a sweet red bell pepper, two stalks of celery, a handful of cherry tomatoes, and a spicy jalapeno pepper. And I dip all of these in a big bowl of silky sultry hummus. My favorite part of this meal is the jalapeno pepper and it's sultry heat. But for some sad reason, for the past two days I have been tricked, the jalapenos were not hot!! What's going on here? does anyone know? Is there a way to tell the hot ones from the fakers when I am grocery shopping? Please help, inquiring spicy minds want to know.