Besides 2015 when Bitcoin and crypto in general seemed to be on the real brink of death having their worst year, today the markets look better than ever before imo - possibly being even highly undervalued.

But it's very, very hard to convince someone that they should head for a long term vision and not be led by short radical market movements. If you take 2015 out of the equation and the short timespan during which BTC has been past $12k, all you're left with is mostly pure profit and every year has been a new high. Even if you had invested once per month ever since BTC was >$12k, you still would've had a profit today as the price crashed a few times.

It all goes down to your own vision over the market.