The phrase "to latch onto" means to grasp or hold on tightly to something, often with great intensity and determination. It can also refer to someone or something that is strongly attracted to an idea, belief, person, or thing, and won't let go of it easily. The term comes from the physical act of latching onto a surface or object, which involves securing two separate pieces together by attaching one end to the other in such a way as to prevent them from being separated again.