Coin - Probability explanation Let's say we flip a fair coin $1$ time. The probability of obtaining at least one heads is $50\%$. 
However let's say we flip the coin $2$ times. The probability of obtaining at least one heads becomes $75\%$. 
I can't seem to wrap my head around why our probability of obtaining at least one heads increases as we increase the number of times we flip the coin since each flip of the coin is an independent event and each time we have a $50\%$ of getting heads so shouldn't the probability of obtaining at least one heads be $50\%$?

If you are going to flip the coin twice, you know that if do fail to obtain a head on the first try, there will still be another chance, so how can the probability of obtaining at least one head in two flips be any thing but greater than the probability of obtaining one head on the first flip?
$$\begin{align} & \; \mathsf P(\text{at least one head in two flips}) \\[1ex] = & \;\mathsf P(\text{head first try}) + \mathsf P(\text{tail first try})\,\mathsf P(\text{head second try}) \\[1ex] = & \quad \frac 1 2 + \frac 1 2\times \frac 1 2 \\[1ex] = & \qquad \frac 3 4\end{align}$$
