I'm 35, male, having constant short term memory loss. Multiple times per day, I can't remember words or why I entered a room. Any ideas?

Doctor. You should go see a doctor to see if there is any treatable cause for your memory problems.
Many possibilities. Medication side-effect (tranquilizers, high-dose antihistamines, etc). Chronic alcoholism. Head injury/concussion. Thyroid disorder. Vitamin B12 deficiency. Actually, there's a long list. You should be evaluated in person by a doctor. Helpful webpage to get you started: http://www.Nlm.Nih.Gov/medlineplus/ency/article/003257.Htm.