Enthusiasm is a feature that came with the Hobbies feature in The Sims 2: Freetime. It indicates the level of interest a Sim has in a particular hobby. By interacting with objects associated with hobbies, a Sim can increase their enthusiasm and unlock new interactions relates to that hobby. Sims will occasionally dream about their hobbies, and these dreams will raise enthusiasm by a small amount. Enthusiasm will gradually decline over time, so Sims will need to perform hobby-related activities to maintain their enthusiasm levels. If the Sim maximizes their enthusiasm levels, they will receive a plaque from a Hobby Instructor which will be placed in their inventory and can be placed on the wall, and will gain a special memory. Unlike the aspiration bar, enthusiasm does decline while the Sim is sleeping, at work/school, or meditating.

Once a Sim's enthusiasm for a hobby reaches level 3 or 4, the Sim may receive chance cards related to that hobby, and may roll wants and fears related to it. Many outcomes for hobby-related chance cards will either increase or decrease enthusiasm.

All Sims have a predestined hobby, and it will be easier for them to gain and maintain enthusiasm in this hobby. All hobbies except Film and Literature are linked to a skill, and having a higher level in that skill will make it easier for a Sim to gain and maintain enthusiasm in the associated hobby. All hobbies are linked to a couple of the personality scales. Depending on the hobby, having a low or high score on the appropriate scale will make it easier for a Sim to gain and maintain enthusiasm in the hobby. Increasing a Sim's enthusiasm for a hobby becomes harder as the enthusiasm level increases.

As a rule, a Sim's enthusiasm will neither increase nor decrease while on community lots. However, young adult Sims are able to build enthusiasm on university community lots, and Sims can build enthusiasm on the secret hobby lots. Also, the "Instruct in Hobby" interaction is available on community lots.

Sims that are really enthusiastic about a hobby can get "in the zone". When their enthusiasm has reached the maximum level and they are performing an interaction related to that hobby, they will forget about everything around them. Sims "In the Zone" have a glow surrounding them, and if their hobby is Music and Dance they'll hear an audience clapping. The first time a Sim reaches maximum enthusiasm in a hobby, he or she will receive Lifetime Aspiration points. Sims may also have a major want to reach maximum enthusiasm in a hobby.

Unlockable interactions[]

Enthusiasm runs on a 0 to 10.00 scale, and as it increases, various interactions will be unlocked.