That is true, one need to be sure of his investment tactics and know that, what works for a person might hardly work for you, maybe it could be the person is always ready for long term holding, so I think it's very important to have your own strategy than following that of others, although you can still take a clue from them.
Secondly, holders should learn a very important thing which is, not all coins are good for long term and vice versa, some are only good for short term while some good for long term, so let no one be carried away by what the team are saying and leaves his coins for long term while the signs are there it's already for short term.
Talking about long term, a lot of project developers might come with good features and all that, along the line lost it, thus one need to be sure the team are ready to offer or better still know when to change strategy if things are not working as anticipated.