For me, it would depend upon the 'dream' and where everyone else in our family was at.
In the case of 'if he wasn't any good' at the sport he liked, DS may not be very successful in getting us to move somewhere else for more than 2 weeks, put it that way! But I'd do early starts for a sport he wasn't good at but loved all the same.
If I were to become a big dressage star by the time DS is at an age where he is playing sports and is really good, then he may have to learn the art of compromise! However, as that is unlikely to happen, if he were to be a contender for something elite, then I'd consider moving somewhere temporarily for him to give it a red hot go. After all, I have always been one to say 'seize every opportunity', and if that is only allowed to apply to me and DP, then what good am I as a parent?
I'm sure DP would think differently, though. I suggested I could take up the university offer of free travel and accomodation to the Malaysian campus for a semester or two, just to experience it and he didn't even consider the benefits to DS and I, just said "what would I do there? No". So, I don't think he'd consider uprooting himself for someone else's ambitions!
At this stage I have hopes that DS will follow us into either horseriding (convenient, as I ride, too!) or fire brigade comps (convenient, as DP does that and I used to). However, I do realise that he may decide to do something else entirely. I foresee a great future as a stuntman, myself...
I think that I am thinking "I had my time, when it's DS's turn to shine I might have to put myself out for him especially if he's going to be better at what he does than I am at what I do". But even if I AM a champion dressage star, I may decide to shelve it to drive him around to his chosen sport/activity where there are clashes.
It's a tough one.
ETA:
Umm, big call, misty! I don't think it means that! Sure, you do get that, but I don't think this applies to most parents who sacrifice a lot for their kids. I mean, geez, I've just realised that I MAY be willing to sacrifice quite a bit for my son's ambitions so that he can say 'well, at least I gave it a go' and now you're calling me a stage mum? Bit 'arsh, chicky! And not applicable in the least, may I add.:
Sacrificing EVERYTHING (or even just ALOT) just makes you another stage mum, and in my opinion there are anough of those already in the world.
Ha! Just thinking of one such parent who moved country for her son's brilliant elite sport prospects in a winter sport. She's moved from California to Vancouver to support her son's ice hockey career (as he's probably a bit young to make the move himself with no family support) and has other kids at home with her DP, as well as older kids from a previous relationship who have their own lives and one in particular a successful career. This mother has had her own stellar career in something non-sporting and probably considers that she's had her time in the sun and can let her kids shine now. For those who haven't guessed yet, I'm talking about Goldie Hawn. Food for thought.

