Personally, and in my own opinion, we plebs shouldn't treat our little/limited capital like it's Warren Buffett's billions that needs to be "diversified". It will slow down our ROI plus it's probably not needed. Diversification is made to protect capital and control risks because their billions has more to lose in every small market move. For us plebs, if we truly want to make life-changing profit, then, only my personal opinion, we should take more risks and concentrate capital to just one investment that we can have strong conviction to HODL long term. If you ask me, it's a golden opportunity to buy and HODL Bitcoin. 
No, we don't treat our capital like Warren Buffett's or other rich people. We try to arrange our capital to invest in Bitcoin. If we make a profit, we can give more portion to invest in Bitcoin while we can also think about adding more investment so we can increase our investment portfolio. That will give us more profit in the future because we can have many investment and not just in Bitcoin.We can take more risks but we should not break our limit on handling the risks and only take the risk that we can afford. That is one thing that we must remember in investing. If they don't want to confuse handling many investment, yes he can use one investment that he can HODL long term. That means, he can focus on buy and HODL Bitcoin.
We always suggest to HODL Bitcoin to all people because we know that Bitcoin can give a big profit in the future.
@michellee, for me i consider JJG'S advice that after building up your Bitcoin investment portfolio to a certain point of considering diversification, that it is advisable to diversify in to real life investment such as selling commodities, real estate or land, investing in altcoin is more like gambling than investment. Fuck shitcoins, it is important spreading your investment in to different assets classes of which shitcoins is a no no for me I don't know about you, is your choice.
That is just an example because we are in crypto. Investing in other commodities is good, I prefer to invest in gold as starts. I consider that having investment in real estate or land needs more money but we can have an investment in gold. No problem if you don't want to invest in altcoins because that is a personal choice. I make Bitcoin as my main investment but I am trying to build my investment in other things.