I totally appreciate the effort you went to to write this.

You're quite right in that your time is valuable and a lot of people encroach on this time without any respect for just how valuable it is - it's the only resource we cannot renew, at least so far. So your taking the time and effort to write this instead of whatever else it is you could've been doing to further your success is evidence of how important this topic is to you as well. So thank you.

You are from the sound of things in a wonderful and respectful relationship that values your time and needs. This is worth keeping hold of; but many people have absolutely no respect for each others needs in this sense and so walk all over it with the expectation that their partner should be more selfless so they can be more selfish instead of both being selfless towards one anothers needs. Any affront to this perception is considered selfishness on your part.

"Oh you need time to yourself, I will make room and take on responsibility so that you can have that." returned by the favour of "Oh, you need some time to do X, Y or Z activity so you can be fulfilled, you know what, let me take A, B and C off your plate so that you can do that."

This is the difference between a selfless relationship and a one sided relationship where one partner is "You know what, I need this in order to feel fulfilled, so I need you to do X, Y and Z for me so that I can get that fulfilment." "What do you mean you don't have the capacity to do that? You think your time at the pub with your friends is more important than my mental wellbeing?" "Well, you want me to stop doing something that's good for my own mental wellbeing in order for you to satisfy yours."

From the sound of things, you've been on the receiving end of this too, so you understand both sides of this coin.

A balance definitely needs to be struck between the giving of yourself freely to those that are important to you and the expectation of payment in kind. Relationships are a two way street.

With regards to people who approach you for technical assistance in their projects - I've been burned a number of times: Kids with no due dilligence done expecting me to give my all for their success, right up to a sociopath who had done all her due dilligence and had used every developer she could get to do her bidding as stepping stones to her success while taking advantage, not paying them, setting lawyers on them to hand over code she'd not paid for and the whole 9 yards who approached me with a solid prototype, a solid business plan and an NDA that protected her and "a contract that's coming" but was never delivered who convinced me to work on good faith. She was a nasty piece of work. So I understand being taken advantage of and I'm wary of it having been stung for tens of thousands of dollars in payments I will never receive. Thankfully a solid understanding of the DMCA, Copyright Law and lucky timing saved me from her ever being able to publish my work, but that's another story for another time.

My point is: If your friends and business partners are taking advantage without any respect for your needs, they're not your friends. If any contract is too one sided without any consideration for your needs and there is resistance to your needs being met, they don't care about you, only themselves.

If your friendships aren't instrumental in your success and your success is where your personal fulfillment lies, then your friendships should be evaluated in such a way that they bring you that success, not stand in its way... and that's a two way street. You cannot expect your friends to be instrumental in your success without your willingness to be instrumental in theirs. You stand by them as you expect them to stand by you. If one or the other of you is not meeting this basic tenet of friendship, then you need to reevaluate that friendship.