Yes, I sometimes get drunk alone. Not often, maybe once every few weeks. I used to smoke weed alone and read, but I don't do that any more. I used to take ketamine and watch anime, but I don't do that any more. I enjoy my own company and I'm very comfortable with myself. I've been drinking for more than 10 years in this fashion, yet I've never felt addicted, never had my habits impact on my home or social life, never had them complicate my education or employment. I enjoy altered states of consciousness, yet I've somehow managed to avoid becoming a gibbering, homeless wreck - more than that, I've even maintained healthy and involved relationships with many people over the years, some brief & intense and others long-term & steady. Exactly where in that is the problem?