It would just depend on you since most of the investors are planning to HODL their Bitcoin in the long term, so I guess you could probably make it as a retirement plan or something like that but since its a volatile market you cannot expect that the market has already skyrocketed the time you retire, You could probably make a profit or miss the opportunity. In my opinion, you could make Bitcoin your investment but not a retirement thing since this is not a guaranteed cashout like some kind of insurance where you save money then you could just use it when you get old plus you gain some kind of interest. Bitcoin is a risky investment compared to some insurance agency stuff.
For me, you should make Bitcoin something like a bet since even though Bitcoin is a great investment and most people are making trading daily as a source of income, only invest money that you could afford to lose. Also, you might end up selling your Bitcoin at an unfair price if you're going to sell it on your retirement, its better if you're going to watch the market and sell if the market skyrockets.