BTC climbed 2 times to the 65-69K range and then fell to the 30-35K range. These 2 were great opportunities to sell and buy back. But you never know before so I don't regret a thing. There is no guarantee for anything.
What would make you not sell at those points, especially if you started holding when you said you did? I do not think it is a wise decision. Something makes me feel there is a missing information that you have not sold anything from the bitcoin you have since 2013 or is the amount you are holding something very small that can not do anything for you? I find it hard to swallow. I can be wrong on my feeling, i can also be right. Is there any evidence to prove this? That will also help to make more people believe in long term holding if you can provide us this.
I won't sell even if will reach $70,000 this year. But I consider selling 10-15% if it will get into the $1xx,000 range... to be honest I will only sell when I feel it's time to sell it. It just wasn't the time yet.