In the grand scheme of things, nobody held bitcoin for too long, when bitcoin was going for 10$ nobody would have guessed it would be worth $9000, I am almost sure that MOST of those lucky hodlers either forgot they had bitcoin or they were lazy to sell it back then, and once bitcoin went viral they remembered about their holdings, sold and made a fortune, also a huge portion of them had no easy way to sell bitcoin back then so they stored their PK somewhere and retrieved it later when selling bitcoin was much easier. Unless you could foresee the future, I don't think you should be feeling bad about it.