Question about alcohol

Does anybody know why it would take eight shots of vodka to even feel buzzed? Just did eight shots in about 3 hours, just now getting buzzed off it after 8 shots. Do you think it’s just tolerance? I do drink a lot but I don’t think I drink enough to have built up that much tolerance to alcohol. I’d say I drink about 6 to 10 drinks or shots about once every 2 to 3 nights, or at least 3 times a week. Would that be enough to build up a tolerance, enough to not even get buzzed until the 8th shot of liquor after a 3-hour period? thoughts?