I have lost small amount of bitcoin while playing dice and pachinko
but my biggest bitcoin loss is from altcoin investment

The only amount I lost was because scam. Not even while gambling which would be a better way to lose money.
Hopefully i can learn people to not invest in too good to be truth ventures.
Everyone learn from their mistakes like how you did and like how i also did before when i was new to bitcoin, i always used to believe those fake promises of scammers and ponzi websites that they will give us double returns after some days or etc, but then i learnt that they just lie later on when i came to know about everything.
each person must have had a bad experience like I lost a couple of times when investing in cloud mining that makes me think this investment is good, I just need to wait for earnings but unfortunately instead of my money grow even lost quite a lot.