- Bitcoin price is volatile
- best private wallet for Bitcoin (long term)
- best exchange to buy bitcoin
etc
and you also have to be prepared to continue receiving questions from him, it will likely annoy you until your friend really believes in bitcoin, it's not easy to introduce bitcoin to other people, but we have to do that to encourage bitcoin adoption.
Telling people the good sides of Bitcoin without telling them the other sides of Bitcoin is very risky. Newbies also need to be aware that the bitcoin price is very volatile which can either reduce or increase the value of their investments. They should be fully aware of the inherent risks involved in investing in Bitcoin, also the dos and don'ts.The OP might be in some sort of trouble if at the end his friend begins to make losses instead of gains as opposed to what the OP told him and this might affect the friendship in the future.
My question now is that is it wise that I showed him the amount of Bitcoins I have accumulated before he developed interest?
As much as I find this story sketching and a pure work of fiction, I still need to advice. Ten years is a lot to change someone you knew before. Showing your your Bitcoin holdings is not safe at all. It can expose you to different attacks. Your financial information is one of the things you should keep private. Those you trust can change any moment.