I think that the best time to buy bitcoin is around 2k but i doubt that that will happen i think that bitcoin will keep having a high value.
And maybe the value be so high that everyone will be surprised. I think it might reach 20k.

I don't think bitcoin will be that high in value for a long time but i think that the bitcoin won't die anytime soon. So i think it is still save for you to invest in bitcoin.
But you should wait for the value to drop first so you will make sure you won't lose money.

The best thing to probably do is to tell them how much money you made and let them see that it is real by cashing out.
Eventually they want to get so much btc to and want  to invest in it tat is how i got interested in bitcoin.

I think you are right because there is no way you can now when the value will go down or go up but sometimes you can like see it drop and maybe then is the right time to put some time to see if it really goes down or will go up again.