I have a few grudge mountains but Shasta is at the top of the list. I made five attempts before finally making the summit.
May 2009 1st attempt, solo day-trip, good weather & snow conditions, I skinned up Avalanche Gulch to 11,000' & ran out of water, rookie mistake.
May 2010 2nd attempt talked some friends into joining me. waited out weather for a few days in town then spent two days on extended approach to Clear Creek route. Ran out of time at 9,000' had to bail.
June 2011 3rd & 4th attemps, rained off of Clear Creek while camping at 9,000', regrouped and made single day attempt on Avalanche Gulch two days later, made it to 12,000' when a friend was hit by rime ice/rock and slid 500 feet before self arresting, sustaining minor injuries and broken crampon, aborted attempt.
May 2012 5th attempt, skinned up Avalance Gulch to 12,000' ditched skis, cramponed to the top of Misery Hill 13,960 +/-, I felt really ill, even with the summit pinnacle in sight I couldn't conjure up the will to finish, turned back and felt fine after descending below 13,000'
September 2012, 6th attempt, late season, little snow/ice on Clear Creek route, one partner, single push, long day, no drama, summited, no big deal, anti-climatic!