After Jane saves Rochester's life by putting out the fire in his bed, she reflects:
I regained my couch, but never thought of sleep. Till morning dawned I was tossed on a buoyant but unquiet sea, where billows of trouble rolled under surges of joy. I thought sometimes I saw beyond its wild waters a shore, sweet as the hills of Beulah; and now and then a freshening gale, wakened by hope, bore my spirit triumphantly towards the bourne: but I could not reach it, even in fancy a counteracting breeze blew off land, and continually drove me back. Sense would resist delirium: judgment would warn passion. Too feverish to rest, I rose as soon as day dawned.
Why might Jane imagine herself tossing about on the sea?