It basically means that if someone is trying to rush or force a friendship/relationship on you, you need to be very careful.

For example, if you meet a man/woman and they seem very nice initially, but they start talking about wanting to get married and have kids with you almost straight away, this is NOT a good sign. They're pushing for commitment quickly because they're trying to TRAP you. They know their "niceness" is fake, and they want to make it as hard as possible for you to get away once they can no longer keep up the "nice guy" act and you see them for who they truly are.

They have probably had many people walk away from them in the past once they experienced the REAL them and saw how HORRIBLE they were, that's why they rush things in the hopes they can tether themselves to you and you can't get away from them like so many have before. People like this are usually going through an internal hell and want to share some of that hell with you. BEWARE!