user136218: Yeah, title says it all, I lost my passphrase from my Bitcoin Core wallet I made in 2009, losing around 3.200.000€ ( 150 BTC ).
I would love to know if there's any possible way I could recover the passphrase, there is no way I remember it or that I'm able to recover it myself.

user13866: There is no way to recover a lost passphrase if ...

All the written copies you made and kept in safe places have been destroyed or lost.
Any copies stamped into fireproof metal and kept in safe places have been destroyed or lost.
Your inheritence arrangements have all been lost. See Husband Father Uncle Brother You Died
You cannot remember the phrase, or almost all of it.

The passphrase (AKA password) in Bitcoin core is used to encrypt the private keys in the wallet data file. If it were possible to recover the passphrase without any knowledge of it, the wallet developers would have failed, Bitcoin core would have its reputation destroyed and no-one would use it.
It is of fundamental importance to Bitcoin core that it not be possible to do what you ask.
There are programs† which can assist in trying millions of variations of a partially remembered passphrase - but for these to have any reasonable chance of success, the amount of the passphrase that was forgotten or lost must be absolutely minimal. You must know almost all of the passphrase.

You will of course be contacted by people claiming to be able to help but they will all be scammers. Once they have gained your confidence they will promise you your 3.200.000€ in return for a small fee with whatever imaginative fee-name they think you will find plausible.

Related

Are there Bitcoin password crackers I can use to recover forgotten passwords?
†Example: BTCrecover tutorial
Forgotten password for wallet. Must a password be entered before spending?
Forgotten wallet password (bitcoin-qt)
I've forgotten the password to my wallet but can still access it, can I get my Bitcoins out?



136218: <p>Yeah, title says it all, I lost my passphrase from my Bitcoin Core wallet I made in 2009, losing around 3.200.000€ ( 150 BTC ).</p>
<p>I would love to know if there's any possible way I could recover the passphrase, there is no way I remember it or that I'm able to recover it myself.</p>
 13866: <p>There is no way to recover a lost passphrase if ...</p>
<ul>
<li>All the written copies you made and kept in safe places have been destroyed or lost.</li>
<li>Any copies stamped into fireproof metal and kept in safe places have been destroyed or lost.</li>
<li>Your inheritence arrangements have all been lost. See <a href="https://bitcoin.stackexchange.com/q/93978/13866">Husband</a> <a href="https://bitcoin.stackexchange.com/q/91937/13866">Father</a> <a href="https://bitcoin.stackexchange.com/q/48178/13866">Uncle</a> <a href="https://bitcoin.stackexchange.com/q/101431/13866">Brother</a> <a href="https://bitcoin.stackexchange.com/q/3359/13866">You</a> <a href="https://bitcoin.stackexchange.com/q/9282/13866">Died</a></li>
<li>You cannot remember the phrase, or almost all of it.</li>
</ul>
<p>The passphrase (AKA password) in Bitcoin core is used to encrypt the private keys in the wallet data file. If it were possible to recover the passphrase without any knowledge of it, the wallet developers would have failed, Bitcoin core would have its reputation destroyed and no-one would use it.</p>
<p>It is of fundamental importance to Bitcoin core that it not be possible to do what you ask.</p>
<p>There are programs† which can assist in trying millions of variations of a partially remembered passphrase - but for these to have any reasonable chance of success, the amount of the passphrase that was forgotten or lost must be absolutely minimal. You must know <em>almost</em> all of the passphrase.</p>
<hr />
<p>You will of course be contacted by people claiming to be able to help but they will all be scammers. Once they have gained your confidence they will promise you your 3.200.000€ in return for a small fee with whatever imaginative fee-name they think you will find plausible.</p>
<hr />
<p>Related</p>
<ul>
<li><a href="https://bitcoin.stackexchange.com/q/3313/13866">Are there Bitcoin password crackers I can use to recover forgotten passwords?</a></li>
<li>†Example: <a href="https://github.com/gurnec/btcrecover/blob/master/TUTORIAL.md#btcrecover-tutorial" rel="nofollow noreferrer">BTCrecover tutorial</a></li>
<li><a href="https://bitcoin.stackexchange.com/q/99630/13866">Forgotten password for wallet. Must a password be entered before spending?</a></li>
<li><a href="https://bitcoin.stackexchange.com/q/17028/13866">Forgotten wallet password (bitcoin-qt)</a></li>
<li><a href="https://bitcoin.stackexchange.com/q/17610/13866">I&#39;ve forgotten the password to my wallet but can still access it, can I get my Bitcoins out?</a></li>
</ul>
<hr />
