For her, being with you also means sacrifices. In today's culture of instant gratification and "me me me" this concept evades many people. A long term relationship involves sacrifices throughout. This may mean you giving up your dream of BASE jumping today and getting nothing "in return" for decades. Somewhere down the line, she may find herself making huge sacrifices for you. Or she may not.
I'd be willing to lay real money on the latter....
However, the only way you will ever be happy is if you truly understand how fortunate you are to have the opportunity to sacrifice something for someone you love, someone who loves you and someone who is perfect for you.
oh my.... sorry but thats sweet sacharin bs. He should feel lucky and fortunate that he gets the chance to sacrifice things to someone he loves? Are you a woman? Quite obviously she isnt perfect for him if she makes 'prima donna' demands of him so that she will feel ok....
Tell you what OP... dont do the basejump but also ask her to sacrifice what she likes doing. She will NOT be prepared to do it. Why? Because she will say there is no reason to sacrifice her hobby because its not dangerous etc. She cant be that committed to the relationship if she isnt prepared to understand your feelings ehh

your life with another person requires a "we" mentality
Often hear this bandied around....what you really mean is that it requires a "she" mentality. Guy has to get used to the woman making demands of him. And often you'll find in relationships that IT IS the guy who does all the sacrificing..compromising etc. Whereas the women just sits there and smiles.
If a woman says to you " if you really love me you wouldnt do X" what you thinking that is? Ohh its her concern for your wellbeing etc etc? Think again... she is caught up in HER own feelings (what woman isnt?) So its the old emotional blackmail card she is dealing....dont be manipulated.