This means that in some moments it helps us and in others it prevents us from moving forward with the activities we want to do. In fact, with them you can do special things that are only unlocked by being in a specific emotion. These have the ability to make a Sim feel bad or good depending on the actions they take with other Sims or objects. You don't have to be an expert to know that emotions are one of the most important things in The Sims 4.